Health conspiracy theories: a scoping review of drivers, impacts, and countermeasures

Abstract

Background

Health-related conspiracy theories undermine trust in healthcare, exacerbate health inequities, and contribute to harmful health behaviors such as vaccine hesitancy and reliance on unproven treatments. These theories disproportionately impact marginalized populations, further widening health disparities. Their rapid spread, amplified by social media algorithms and digital misinformation networks, exacerbates public health challenges, highlighting the urgency of understanding their prevalence, key drivers, and mitigation strategies.

Methods

This scoping review synthesizes research on health-related conspiracy theories, focusing on their prevalence, impacts on health behaviors and outcomes, contributing factors, and counter-measures. Using Arksey and O’Malley’s framework and the Joanna Briggs Institute guidelines, a systematic search of six databases (PubMed, Embase, Web of Science, CINAHL, PsycINFO, and Scopus) was conducted. Studies were screened using predefined inclusion and exclusion criteria, with thematic synthesis categorizing findings across diverse health contexts.

Results

The review revealed pervasive conspiracy beliefs surrounding HIV/AIDS, vaccines, pharmaceutical companies, and COVID-19, linked to reduced vaccine uptake, increased mistrust in health authorities, and negative mental health outcomes such as anxiety and depression. Key drivers included sociopolitical distrust, cognitive biases, low scientific literacy, and the unchecked proliferation of misinformation on digital platforms. Promising countermeasures included inoculation messaging, media literacy interventions, and two-sided refutational techniques. However, their long-term effectiveness remains uncertain, as few studies assess their sustained impact across diverse sociopolitical contexts.

Conclusion

Health-related conspiracy theories present a growing public health challenge that undermines global health equity. While several interventions show potential, further research is needed to evaluate their effectiveness across diverse populations and contexts. Targeted efforts to rebuild trust in healthcare systems and strengthen critical health literacy are essential to mitigate the harmful effects of these conspiracy beliefs.

Introduction

Conspiracy theories have become a significant barrier to global health efforts. They erode public trust, promote questionable health behaviors, and widen health disparities. These theories often stem from historical injustices, political ideologies, and social anxieties, and their impact has been amplified by digital communication platforms. For example, beliefs about HIV/AIDS being a sinister tool of oppression [1, 2] or claims that vaccines are deliberately designed to cause infertility or autism [3, 4] have contributed to reduced health-seeking behaviors and increased vaccine hesitancy.

The consequences of these health-related conspiracy theories are wide-ranging. They influence psychological, social, and behavioral outcomes. They discourage participation in biomedical research [2], reduce vaccine uptake [4, 5], and are associated with increased anxiety and depression [6, 7]. Marginalized communities are particularly vulnerable, as conspiracy beliefs exacerbate existing health inequities and limit access to accurate health information and care. These disparities are often compounded by systemic factors such as educational inequalities, socioeconomic barriers, and cultural mistrust of health systems [1, 8,9,10]. Understanding these effects is crucial for designing targeted interventions that can counteract the negative influence of conspiracy theories.

The spread of conspiracy theories is driven by multiple factors, including individual psychological tendencies, social structures, and systemic distrust. Cognitive biases, such as susceptibility to fear-based messaging and low levels of analytical thinking, increase the likelihood of adopting conspiratorial beliefs [11, 12]. Additionally, structural factors, such as political instability, media misinformation, and reliance on non-credible sources, have facilitated the dissemination of these narratives [13, 14]. Digital platforms have further accelerated the spread, with social media algorithms prioritizing engaging but unverified content, as seen during the Zika outbreak and COVID-19 pandemic [14, 15]. Social media platforms such as Facebook, YouTube, and Twitter have been found to amplify misinformation by prioritizing sensational content that garners high engagement [15]. During the COVID-19 pandemic, false claims about vaccines and treatments gained traction through viral videos, automated bots, and coordinated disinformation campaigns [14, 15]. Similarly, search engines and video recommendation algorithms contribute to misinformation exposure by steering users toward unverified or conspiratorial content over time [15]. These factors make conspiracy theories highly accessible and reinforce users’ pre-existing beliefs [15,16,17,18].

Efforts to address these conspiracy theories have yielded varied effectiveness, influenced by the type of intervention and contextual factors. Educational interventions, such as inoculation messages and media literacy programs, have shown promise in reducing susceptibility to misinformation, but their long-term impact remains uncertain, particularly in digital spaces where new conspiratorial content continuously emerges [16, 17]. Similarly, strategies aimed at enhancing trust in health institutions and promoting analytical thinking have demonstrated effectiveness, but their success often depends on sociopolitical context, cultural beliefs, and pre-existing mistrust in authorities [18, 19]. Research suggests that even well-designed interventions may require ongoing reinforcement to sustain their impact, as exposure to misinformation can erode prior corrective efforts over time [8, 20]. These challenges highlight the need for adaptive and localized approaches that consider the broader ecosystem in which conspiracy theories spread.

Given the growing influence of health-related conspiracy theories, this scoping review aims to systematically map and synthesize existing research by addressing four critical questions:

• 1. What are the most common conspiracy theories in the health sector?

• 2. How do conspiracy theories influence health behaviors, attitudes, and outcomes?

• 3. What factors contribute to the spread of conspiracy theories in the health sector?

• 4. What strategies have been proposed or implemented to address conspiracy theories in healthcare?

This is the first scoping review to provide a structured synthesis of research on health-related conspiracy theories across multiple disciplines. By integrating findings from diverse methodologies, as well as including cross-sectional studies, experiments, and content analyses, this review offers a comprehensive framework for understanding the impact of conspiracy theories on public health. Additionally, it highlights the critical link between conspiracy beliefs and health equity, emphasizing the need for strategies that address disparities in health outcomes and access to care. The insights gained from this analysis will support the development of evidence-based interventions and policy recommendations aimed at reducing the harm of conspiracy beliefs and strengthening trust in health systems.

Methodology

Design

This scoping review systematically explored the literature on health-related conspiracy theories. It followed the framework outlined by Arksey and O’Malley (2005) [19], as further refined by Levac et al. (2010) [20] and the Joanna Briggs Institute (JBI) guidelines. The scoping review approach is designed to map existing evidence comprehensively, identify research gaps, and provide an overview of the key findings in this emerging area. To ensure methodological rigor and relevance, this study relied exclusively on primary research articles.

Search strategy

The search strategy was developed to systematically identify primary research articles from six major databases: PubMed, Embase, Web of Science, CINAHL, PsycINFO, and Scopus. Boolean operators were used in the search query: (“conspiracy theory” OR “misinformation” OR “health rumors” OR “health myths”) AND (“healthcare” OR “public health” OR “medical sector”). The search included all English-language publications available up to October 30, 2024. The terms and structure of the search were tailored to each database’s specific indexing vocabulary, ensuring precision and inclusiveness. Duplicate records were removed using EndNote software, and only peer-reviewed primary research articles were considered for inclusion.

Inclusion and exclusion criteria

To maintain a focused scope, the review applied specific inclusion and exclusion criteria. Included studies addressed conspiracy theories related to health, healthcare, or public health campaigns, and explored their prevalence, impacts, contributory factors, or mitigation strategies. Studies employing any primary research design (quantitative, qualitative, or mixed-methods) were included. Excluded studies were those having topics unrelated to health, published in non-English languages, or classified as editorials, opinion pieces, conference abstracts, dissertations, or secondary analyses.

Study selection and data extraction

Two reviewers independently screened the titles and abstracts of the identified studies to ensure they met the inclusion criteria. Full-text screening followed for studies deemed potentially relevant. Discrepancies were resolved through discussion between the reviewers. A standardized data extraction form was developed collaboratively to capture essential information, including authorship, publication year, country, study design, and key findings. The extraction process focused on answering the predefined research questions related to the prevalence, influence, contributing factors, and mitigation strategies of health-related conspiracy theories. Figure 1 presents the PRISMA diagram of the study selection process.

Data synthesis

Thematic analysis was conducted to synthesize data from the included studies. The findings were organized according to the research questions, highlighting patterns and trends in the literature. Results are presented in narrative and tabular formats to summarize the prevalence and impacts of conspiracy beliefs, the factors contributing to their spread, and the strategies for combatting them.

Fig. 1

PRISMA

Results

Characteristics of the studies

Twenty-five included studies examined various aspects of health-related conspiracy theories by focusing on their prevalence, psychological impact, and influence on health behaviors and public trust (Table 1). Early research explored AIDS-related conspiracy beliefs and their effects on biomedical research participation [2], government mistrust, and HIV testing [1], including knowledge among South African adolescents [21]. Broader conspiracy theories and their psychological associations were also analyzed, particularly links between Medical Conspiracy Theories (MCTs), which involve distrust in healthcare systems and medical interventions, and Modern Health Worries (MHWs), which reflect fears about environmental and technological health risks [24].Studies investigated the spread of Zika-related rumors [14], vaccine misinformation [3], and the role of social media in amplifying misinformation. The COVID-19 pandemic intensified research into conspiracy beliefs among healthcare workers [6], their association with mental health outcomes [7], political ideology [13], and social determinants like trust and ideological orientation [8]. Additionally, interventions such as infographics to improve trust in science [22], fact-based and logic-based inoculation messages [15, 23], and media literacy strategies were assessed for effectiveness in countering conspiracy beliefs [4, 17]. Other studies explored theoretical predictors, including the Theory of Planned Behavior (TPB), which suggests that vaccine hesitancy is influenced by attitudes, perceived social norms, and perceived behavioral control, and the Health Belief Model (HBM), which posits that individuals’ decisions about vaccines depend on perceived susceptibility to disease, perceived benefits, and barriers to vaccination [26]. Additionally, research examined the role of influencers in spreading misinformation through parasocial relationships and gendered narratives, which shape public perceptions of vaccine risks and benefits [27].

Study characteristics varied widely in sample size, setting, and target populations. Sample sizes ranged from 165 students [23] to large-scale surveys with 45,772 participants across 66 countries [16]. Research settings included online surveys [17, 22, 24], hospital-based studies in Ecuador [6], and community-based studies in South Africa [21]. Analysis of social media helped in understanding the dissemination of misinformation [13, 18, 25].

The included studies covered diverse populations, from healthcare workers [6] and adolescents [21] to general adult populations across different countries [5, 10]. Additionally, some studies focused on niche online communities, such as White nationalist forums and wellness influencers, to explore ideological and commercial motivations behind misinformation [18, 25].

Table 1 Characteristics of included studies

Key findings related to conspiracy theories

Conspiracy theories influence health behaviors, attitudes, and public trust across various contexts. Early studies reported significant belief in AIDS-related conspiracies, particularly among marginalized groups, with 27.8% of Black and 23.6% of Hispanic participants endorsing the AIDS origin conspiracy in 1999–2000, increasing to 34.1% and 21.9% in 2003 [2]. Among older adults (≥ 50 years), 30% believed in AIDS-related conspiracy theories, which increased HIV testing likelihood but also reduced trust in government [1]. In South Africa, 8.6% of adolescents believed in HIV-related theories, with prevalence higher among men, the unemployed, and those who had lost relatives to HIV [21]. COVID-19-related rumors had widespread psychological, behavioral, and societal effects, with 24.2% of healthcare workers in Ecuador believing COVID-19 was created in a lab, a belief associated with higher anxiety, distress, and lower job and life satisfaction (p < 0.05) [6]. Similar associations between conspiracy beliefs and anxiety (r = 0.087, p < 0.05) or depression symptoms (r = 0.108, p < 0.05) were found in Poland [7]. In Spain, conspiracy beliefs correlated with lower vaccination rates, (r = -0.42, p < 0.001) particularly among individuals with extreme-right ideological orientations [8]. Studies across 66 countries showed that stronger endorsement of conspiracy theories was linked to lower compliance with public health measures (β = -0.37, p < 0.01), with a greater impact in developed nations [16]. In the UK, government mistrust fueled by conspiracy beliefs reduced vaccine intentions [12], while in Australia, perceived health threats and anomie mediated vaccine hesitancy [5]. Exposure to online misinformation reduced vaccination intent by over 6% in the UK and the USA [4].

Efforts to counter conspiracy theories showed mixed results. Brief exposure to an infographic explaining the scientific process increased trust in science and reduced misinformation belief indirectly [25]. Inoculation messages promoting vaccine acceptance were most effective in low-trust settings [17]. Fact-based and logic-based inoculation treatments reduced susceptibility to anti-vaccination propaganda, though they did not protect against other conspiracy beliefs [16]. Media literacy interventions increased skepticism toward both fake and real news, showing potential unintended consequences [18]. Social media platforms played a central role in amplifying conspiracy theories. During the Zika virus outbreak, rumors were shared three times more often than verified information [14]. On Twitter, misinformation discourse was dominated by conservative users, who frequently spread conspiracy theories about Bill Gates, the Chinese Communist Party, and the Deep State [13]. On Instagram, wellness influencers leveraged parasocial relationships and gendered narratives to spread vaccine misinformation for profit through affiliate links and product promotions [27]. A qualitative analysis of White nationalist forums identified four dominant misinformation themes—scientific skepticism, conspiracy claims, sociopolitical concerns, and containment opposition—contributing to vaccine rejection [15]. Medical conspiracy theories strongly predicted health worries, particularly among individuals with lower education, lower health literacy, and greater reliance on non-professional health information sources [9, 24]. Socioeconomic status, trust in political institutions, and moral emotions significantly influenced belief in health-related misinformation [10]. A study in India found that lower socioeconomic status, right-leaning ideology, and negative moral emotions were key predictors of conspiracy theory endorsement [10]. In the USA and Canada, conspiracy beliefs negatively influenced vaccination attitudes, perceived behavioral control, and subjective norms, particularly through factors outlined in the TPB and the HBM, such as perceived susceptibility, severity, and perceived barriers [26].

Health conspiracy beliefs

Conspiracy theories in the health sector encompass a broad range of beliefs. They are often rooted in mistrust of governments, pharmaceutical industries, and health systems. The AIDS origin theory claims that HIV was created by the government or pharmaceutical companies as a tool for genocide or population control and that a cure is being withheld [1, 2, 21]. While these beliefs did not reduce participation in biomedical research, they correlated with higher mistrust, particularly among Black and Hispanic populations in the U.S [2]. Similarly, vaccination-related conspiracies, such as claims that vaccines cause autism or are used to hide tracking devices, have persisted for years [23, 24], leading to reduced vaccination uptake and increased preference for complementary and alternative medicine (CAM) [24] (Table 2).

The spread of misinformation during public health crises, such as the Zika virus and COVID-19 pandemic, has further amplified conspiracy beliefs. Zika-related stories included claims that the virus was linked to larvicides and pesticides, while it was also dismissed as a low-risk issue [14]. COVID-19 conspiracy theories ranged from claims that the virus was intentionally developed in a lab, that it was a military weapon, was being spread by 5G networks, or was a hoax for financial or political gain [6, 13, 16, 22]. These beliefs also include extreme narratives, such as the idea that COVID-19 vaccines contain microchips for social control [15, 18].

Mistrust in pharmaceutical companies and governments is a recurring theme in health-related conspiracies. Claims that COVID-19 vaccines alter DNA, cause infertility, or serve as bioweapons reflect deep-rooted fears about vaccine safety and motives [4, 5]. Similarly, the endorsement of alternative medicine and allegations of suppressed natural cures for profit have fueled conspiratorial thinking about antidepressants and cancer treatments [11, 17]. Such narratives contribute to the erosion of trust in established healthcare systems and practices.

Conspiracy theories often intersect with broader sociopolitical themes that reflect public anxieties and ideological divisions. Beliefs about COVID-19 being a bioweapon, an example of government overreach through lockdowns, or that vaccines are tools for authoritarian control exemplify how health crises become platforms for political polarization [7, 8, 25]. Specific claims, such as those associating vaccines with ferrous metals or microchips, highlight how fear and misinformation spread through targeted campaigns and social media [9, 10].

The persistence of these beliefs, even after corrections, emphasizes the challenges of combating misinformation. While repeated corrections can help counteract belief regression, entrenched narratives—such as the idea of COVID-19 being a hoax or a government conspiracy—continue to thrive across diverse populations and regions [26, 27]. Such beliefs not only undermine public health efforts, but they also exacerbate divisions within societies.

Table 2 Popular conspiracy theories and their impact

Conspiracy theories in different health domains

Conspiracy theories have shaped public behaviors across many health domains. In the context of HIV/AIDS, beliefs have included claims that the virus was created by governments or pharmaceutical companies for population control, along with accusations that a cure is being withheld to target specific groups [1, 2]. Similar conspiracy narratives persisted among South African adolescents, who attributed HIV’s origins to the US government, drug companies, or scientists, highlighting deep-rooted mistrust in health authorities [21].

Vaccination and water safety have also been targets of conspiracy theories, with persistent claims linking vaccines to autism and fluoride in drinking water to hidden contaminants. These narratives contribute to vaccine hesitancy and broader distrust in public health initiatives [24]. During the Zika outbreak, misinformation circulated about the virus being linked to larvicides and pesticides as causes of birth defects while simultaneously downplaying its risks, creating widespread public confusion [14]. Similar patterns of distrust emerged around the measles, mumps, and rubella (MMR) vaccine, particularly in the United States, where misinformation has fueled skepticism regarding vaccine safety [3, 23].

The COVID-19 pandemic further amplified conspiracy beliefs on a global scale. Claims varied from COVID-19 being a bioweapon or a fabricated crisis for financial and political gain to allegations that vaccines alter DNA, contain microchips, or serve as tools for mass control [4, 13, 15, 18, 22]. Such narratives have substantially undermined public trust and increased vaccine hesitancy, with studies linking conspiracy beliefs to lower vaccination rates [5, 8, 16]. Additionally, misinformation about alternative COVID-19 treatments, including hydroxychloroquine and bleach as treatment measures, exacerbated health risks and fueled skepticism toward medical guidance [13].

Conspiracy theories have also harmed mental health and well-being. Widespread claims that antidepressants are overprescribed, ineffective, or harmful reflect broader distrust in pharmaceutical companies and contribute to reliance on alternative therapies [11]. Among healthcare workers, conspiracy beliefs about COVID-19 being created in a lab have been associated with higher levels of anxiety and distress, along with lower job and life satisfaction [6].

Misinformation has extended into cancer treatment, with narratives promoting alternative cures and fostering mistrust in conventional medicine, ultimately compromising public understanding of evidence-based interventions and delaying critical treatments [17]. Efforts to combat misinformation have included interventions such as inoculation messages and media literacy programs. However, their effectiveness in addressing deeply ingrained conspiracy beliefs remains inconsistent [23, 26, 27].

Impact of conspiracy beliefs on health behaviors and outcomes

Conspiracy beliefs often undermine public health efforts and promote distrust in healthcare systems. While AIDS-related conspiracy beliefs did not reduce participation in biomedical research, they highlighted systemic mistrust, particularly among minority populations [2]. Similarly, these beliefs were linked to increased HIV testing but also reinforced skepticism about HIV prevention and treatment, demonstrating their complex and contradictory effects on health behaviors [1, 21]. More broadly, conspiracy theories have fueled skepticism toward modern medicine and increased reliance on complementary and alternative medicine (CAM) [24].

During public health crises, conspiracy theories played a role in eroding trust in health authorities and reducing compliance with protective measures. For instance, misinformation surrounding the Zika virus led to diminished risk perception and lower adherence to mosquito control efforts [14]. Similarly, COVID-19 theories contributed to distrust in public health recommendations, encouraged harmful behaviors such as bleach ingestion, and intensified xenophobia and political polarization [13]. These beliefs also resulted in lower compliance with public health regulations, including mask-wearing and social distancing, and heightened resistance to vaccination programs worldwide [16, 25].

Vaccine hesitancy has emerged as a persistent consequence of conspiracy beliefs, particularly those depicting vaccines as unsafe or as instruments of societal control. Claims that COVID-19 vaccines alter DNA or contain microchips have reduced vaccination intent and contributed to negative attitudes toward vaccines [4, 15]. Additionally, distrust in government and perceived health threats have acted as mediators, further strengthening the link between conspiracy beliefs and vaccine hesitancy [5]. In Spain, for example, conspiracy-driven skepticism influenced vaccination decisions among both adults and their children, leading to lower immunization rates [8].

Beyond vaccination, misinformation has exacerbated psychological distress and deterred individuals from seeking medical or psychological help. Conspiracy believers have reported higher anxiety levels, lower job and life satisfaction, and a greater reluctance to engage with healthcare services [6, 11]. In some cases, misinformation has led individuals to favor self-controlled protective behaviors, such as increased handwashing, over scientifically validated interventions like vaccination and diagnostic testing [12]. Even after being corrected, conspiracy beliefs often persist, reflecting the deep-seated nature of these narratives and their resistance to factual counterarguments [26].

The broader consequences of conspiracy beliefs extend to misinformation about cancer treatments and vaccine mandates. Cancer-related conspiracy theories have fueled skepticism toward pharmaceutical interventions, reducing trust in evidence-based medicine and delaying critical treatments [17]. Likewise, vaccine hesitancy has encouraged the use of alternative therapies and motivated some parents to opt for homeschooling to bypass vaccine requirements, particularly in the US [10, 18].

Impact of conspiracy beliefs on health

Conspiracy theories have far-reaching effects across behavioral, psychological, social, and cognitive domains. They can shape health outcomes and public attitudes in profound ways.

Psychologically, conspiracy beliefs intensify emotions such as fear, anxiety, and mistrust, often leading to negative mental health outcomes. For instance, healthcare workers in Ecuador who believed that COVID-19 was developed in a lab reported heightened distress and lower job satisfaction [6]. Vaccine-related conspiracy beliefs also fueled skepticism and fear, further eroding trust in health authorities [3, 7]. In Spain, such beliefs were linked to increased anxiety and depression [8]. Broader concerns, including fears of government surveillance and societal control, contributed to significant emotional burdens worldwide [10, 27].

Behaviorally, conspiracy beliefs often lead to non-compliance with health recommendations, vaccine hesitancy, and reliance on unproven treatments. While AIDS-related beliefs did not directly reduce participation in biomedical research, they contributed to skepticism and distrust, particularly among minority populations [2]. Misinformation surrounding COVID-19 vaccines reduced vaccine uptake and adherence to public health measures [4, 5]. In the US, misinformation led to dangerous behaviors, such as drinking bleach as a supposed cure [13]. Similarly, distrust in vaccines contributed to reliance on alternative treatments and refusal of routine immunizations, further compromising public health efforts [11, 18].

Socially, conspiracy beliefs undermine trust in health systems and deepen societal divisions. Public health measures, such as masking, social distancing, and vaccination campaigns, faced resistance due to widespread mistrust fueled by conspiracy narratives [25]. Multinational studies demonstrated that belief in COVID-19 conspiracies significantly lowered compliance with public health guidelines, illustrating a global pattern of eroded collective trust [16]. In Spain, conspiracy beliefs directly contributed to lower vaccination rates and reduced herd immunity, further illustrating their societal ramifications [8]. Additionally, distrust in healthcare institutions and governments acted as a barrier to effective health interventions [9, 17, 26].

Cognitively, conspiracy beliefs impair critical thinking and the ability to distinguish accurate information from misinformation. Media literacy interventions sometimes increased skepticism toward both falsehoods and verified information, complicating efforts to correct misinformation [15, 23]. The phenomenon of belief regression—where false beliefs persist even after correction—demonstrates the enduring cognitive impact of conspiracy narratives on decision-making [26]. Across health domains, these findings highlight the widespread influence of conspiracy beliefs on individual behaviors, mental health, and societal trust [1, 14, 21, 24].

Factors contributing to the spread of conspiracy theories

The spread of health-related conspiracy theories is influenced by a combination of sociopolitical, psychological, and informational factors. Mistrust in government is a recurring theme, particularly among minority groups with histories of discrimination and systemic inequality [1, 2]. In South Africa, structural factors such as racial oppression, poverty, and HIV-related stigma reinforce skepticism toward health interventions [21]. Other contributors include religious beliefs, the use of CAM, and self-reported poor mental health [24](Table 3).

The role of alternative media and the absence of evidence-based information in early public health messaging contribute to misinformation, as seen during the Zika outbreak [14]. Social media platforms further amplify conspiracy narratives by creating echo chambers that foster distrust in authorities [3, 6]. Political ideology and polarization intensify these beliefs, particularly in discussions surrounding vaccines and public health mandates [13]. Additionally, low trust in science, political conservatism, and the perceived severity of health crises contribute to the persistence of conspiracy theories [22].

A decline in trust toward health authorities, combined with feelings of powerlessness, has been linked to changes in health behaviors [11]. Misinformation spreads more rapidly in environments where individuals rely on social media for news and have lower levels of analytical thinking [12]. Psychological factors, including beliefs in global conspiracies, concerns about information control, and personal well-being anxieties, also play a role in shaping conspiracy beliefs [7]. Factors such as anomie, political ideology, and perceived health threats mediate the relationship between conspiracy beliefs and vaccine hesitancy [5].

Misinformation spreads particularly rapidly in regions with low political trust [15]. Cognitive biases, including memory failures, resistance to corrections, and shallow information processing make misinformation difficult to counteract [26]. The prevalence of social media, trust deficits in institutions, and higher Human Development Index (HDI) scores in developed nations have all been associated with the increasing acceptance of conspiracy theories [16]. In Spain, conspiracy narratives are reinforced by low trust in government health authorities, skepticism toward pharmaceutical companies, and alignment with extreme right-wing political ideologies [8].

The politicization of science and the strategic use of scientific language by extremist groups, including those with White nationalist ideologies, further erode public trust in evidence-based information [25]. Misinformation, emotional narratives, and distrust in public health institutions contribute to vaccine hesitancy and resistance to public health measures [23]. Socioeconomic factors, including low income, right-leaning ideology, negative moral emotions, and mistrust in political institutions, are strong predictors of belief in health-related conspiracies [10]. Additionally, false beliefs about cancer treatments, distrust in experts, and low digital and health literacy increase vulnerability to misinformation [17].

Educational background, medical mistrust, and reliance on non-credible sources further contribute to the spread of conspiracy myths [9]. Sociopolitical distrust, the unchecked spread of misinformation through social media, and a perceived lack of transparency from authorities reinforce the persistence of these beliefs [27]. Furthermore, vaccine-related misinformation is often propagated by wellness influencers through parasocial relationships, platform affordances, institutional skepticism, and gendered narratives [18].

Table 3 Factors contributing to the spread of conspiracy theories

How contributing factors spread conspiracy theories

The spread of health-related conspiracy theories is driven by a combination of historical, psychological, sociopolitical, and technological factors that reinforce skepticism and amplify misinformation. Historical mistrust, particularly among minority populations, stems from events like the Tuskegee Study and continues to undermine confidence in public health initiatives. This mistrust is more pronounced among individuals with lower education and income levels [2]. Additionally, sociocultural factors such as religious beliefs, reliance on CAM, and poor mental health contribute to conspiracy thinking by fostering skepticism toward biomedical science [1, 21, 24].

The role of the media—both alternative and social—has been pivotal in spreading misinformation. During the Zika outbreak, the absence of verified content allowed alternative narratives to dominate through emotional appeal and repetition [14]. Similarly, frames emphasizing government collusion or pharmaceutical profiteering make false claims more likely to be believed and shared [3, 6]. Social media platforms act as echo chambers to reinforce pre-existing biases and promote conspiratorial narratives, particularly among conservative users who exhibit greater tolerance for misinformation [13, 22].

Misinformation spreads rapidly, often outpacing corrections. False claims about vaccines, for example, circulate faster than verified information [4, 11]. Contradictions in media reporting further amplify anxiety, leading individuals to seek explanations that align with their pre-existing beliefs [7]. Political ideology, particularly right-wing perspectives, and concerns about societal decline further intensify distrust in government and support for global conspiracy narratives [5, 8].

Cognitive biases and information-processing limitations contribute to the persistence of conspiracy beliefs. Memory failures, shallow engagement with corrective information, and belief regression—where individuals revert to misinformation even after being exposed to fact-checks—hinder efforts to counter false narratives [26]. Low digital and health literacy exacerbate this issue by reducing individuals’ ability to assess the credibility of information, increasing their vulnerability to conspiracy-driven content [9, 17].

Distrust in health systems and scientific institutions is further reinforced by political divisions, emotional messaging, and misinformation disguised in scientific language. Some conspiracy theories incorporate pseudoscientific terminology to appear credible, while others leverage racist or anti-Semitic undertones to delegitimize public health policies [25]. Emotional narratives, particularly those portraying vaccines as harmful or health authorities as corrupt, deepen skepticism and resistance to medical interventions [10, 23]. On social media, influencers use platform features such as Instagram Stories to establish emotional connections with their audience, further amplifying distrust in traditional health sources [18].

Empirical evidence on factors driving conspiracy beliefs

Empirical evidence demonstrates how various factors contribute to the spread of conspiracy theories in health. Mistrust in government and systemic inequalities are consistently linked to conspiracy beliefs, particularly among minority populations. In the United States, conspiracy beliefs were found to be over three times more common among Black and Hispanic individuals compared to White populations, with lower education and income levels serving as strong predictors [2]. Similarly, high levels of mistrust (72%) were associated with reduced HIV testing rates, illustrating the direct behavioral impact of these beliefs [1]. In South Africa, the legacy of AIDS denialism under Thabo Mbeki’s leadership delayed the rollout of antiretroviral therapy, fostering distrust and reinforcing reliance on non-evidence-based explanations, particularly among adolescents in Soweto [21].

The influence of misinformation and alternative media is substantial. During the Zika virus outbreak, 66% of widely shared news stories came from alternative media sources, with misinformation spreading more rapidly than verified content. Delays in fact-checking efforts from organizations like the WHO exacerbated this issue [14]. On social media, trolls and automated bots amplified anti-vaccine messages [3]. In Ecuador, an analysis of online discourse identified over 295,052 mentions of COVID-19 conspiracy theories within just one week [6]. In the US, conservative users dominated five of six major misinformation topics, leveraging ideological filter bubbles to reject public health guidelines [13].

Sociopolitical factors further influence the acceptance of conspiracy beliefs. Misinformation during the 2020 US elections led to measurable declines in vaccine intent, highlighting the intersection of political polarization and health misinformation [4]. Experimental studies showed that exposure to conspiracy theories significantly reduced trust in health authorities, with feelings of powerlessness playing a mediating role in health-seeking behaviors [11]. In Poland, a correlation as high as 0.768 was found between conspiracy beliefs and symptoms of anxiety and depression [7]. In Australia, perceptions of societal decline and anomie contributed to vaccine hesitancy through increased conspiracy endorsement [5].

Cognitive factors also reinforce the persistence of conspiracy beliefs. In a US study, 78% of individuals who initially believed misinformation later misremembered corrections as confirmations, highlighting the challenges of countering falsehoods [26]. On a global scale, conspiracy beliefs were stronger in developed nations, where lower trust in institutions was associated with reduced compliance with public health measures [16]. In Spain, distrust in pharmaceutical companies and extreme-right political ideology were significant predictors of conspiracy beliefs, with individuals identifying as extreme-right exhibiting 0.35 standard deviations higher conspiracy belief levels compared to centrists [8].

The role of social and emotional narratives in spreading conspiracy theories is significant. In the Unites States, conservative media and political figures, including President Trump, actively undermined trust in public health officials. Pseudo-scientific language was also employed to legitimize alternative medicine and conspiratorial claims, including allegations that COVID-19 was a “Jewish hoax” [25]. On social media, influencers used personal anecdotes and religious narratives to gain trust and disseminate vaccine misinformation [18]. In India, regression analysis identified low socioeconomic status, right-leaning ideology, and negative moral emotions as significant predictors of conspiratorial beliefs [10].

Low literacy levels exacerbate susceptibility to conspiracy theories. Individuals with lower education levels were 22% more likely to believe in myths, while those with institutional mistrust had a 72% higher likelihood of endorsing conspiracy beliefs [9]. Misinformation about cancer treatments, paired with low digital literacy, was strongly correlated with both the perceived accuracy and the sharing of inaccurate health-related headlines [17]. Studies have consistently linked reduced vaccination intent with the influence of conspiracy beliefs, highlighting the broad impact of these narratives on public health decision-making.

Strategies to counter health-related conspiracy theories

Efforts to counter the spread of conspiracy theories in health focus on education, trust-building, and strategic communication. Community engagement and culturally relevant educational initiatives play a crucial role in addressing misinformation, particularly among marginalized groups. Targeted campaigns have been developed to promote trust in public health institutions and correct misconceptions among specific populations, such as minorities in the United States and adolescents in South Africa [1, 2, 21] (Table 4).

Educational interventions emphasize the importance of early, accurate information and collaboration with fact-checkers to prevent misinformation from gaining traction. For example, during the Zika outbreak, early exposure to credible information and partnerships with fact-checking organizations were recommended to counter the dominance of alternative media narratives [14]. Visual tools such as infographics explaining the scientific process have been shown to enhance trust in science and reduce susceptibility to misinformation [22]. Additionally, vaccination campaigns incorporating altruistic messaging and structured fact-checking initiatives have demonstrated effectiveness in mitigating conspiracy-driven vaccine hesitancy [4].

Tailored communication strategies targeting populations skeptical of modern medicine have proven effective in improving understanding and trust. Techniques such as two-sided refutational messaging, which presents misinformation before debunking it, have been successfully employed to counter conspiracy narratives [3, 15]. Promoting analytical thinking, fostering transparent dialogue, and addressing logical fallacies within conspiracy beliefs are critical to enhancing public trust in health recommendations [12, 27].

Cognitive-based interventions such as inoculation treatments—both fact-based and logic-based—have been shown to build resistance to misinformation. Strategies that incorporate repeated corrections and deeper cognitive engagement with the facts help overcome psychological barriers to belief revision [23, 26]. Strengthening critical thinking skills and institutional trust is particularly vital in societies with low political or scientific trust [10].

Social media regulation and policy interventions are essential in curbing the spread of misinformation. Suggested measures include suspending accounts that propagate false health claims, limiting external linking features to unreliable sources, and strengthening advertisement guidelines for health-related products [13, 18]. Monitoring extremist forums to identify and counter the misuse of pseudo-scientific language in conspiracy narratives has also been proposed as a preventative measure [25].

Enhancing health literacy and promoting reliance on credible sources form the foundation of long-term misinformation mitigation. Public education on vaccine development, tailored debunking efforts, and encouraging trust in medical professionals and government agencies help bolster resilience against misinformation [9]. Specific media literacy interventions, such as BOAST (health-focused) and broader news literacy training, have demonstrated promise in improving individuals’ ability to discern facts from misleading headlines [17].

Table 4 Strategies to address conspiracy beliefs

How strategies address and mitigate conspiracy beliefs

Efforts to mitigate conspiracy beliefs target their underlying causes while encouraging trust in public health and evidence-based information. Community engagement and educational initiatives address systemic mistrust by involving communities in research, improving public understanding of health policies, and reducing psychological barriers to behaviors such as HIV testing [1, 2]. In South Africa, educating adolescents about the true origins of HIV has reduced reliance on conspiracy narratives, strengthening their understanding of biomedical science [21].

Tailored communication and misinformation correction play a crucial role in countering conspiracy beliefs. Two-sided refutational messages, which present false claims alongside factual rebuttals, have been effective in reducing emotional resistance and improving attitudes toward vaccines and other health measures [3, 15]. Targeted health communication campaigns, particularly those designed for vulnerable populations, enhance the ability to distinguish credible information from misinformation, as demonstrated in Ecuador and other regions [6, 13]. Social media interventions, including flagging false content and limiting the reach of conspiracy theories, encourage self-correction among users and decrease the visibility of harmful narratives [14, 18].

Building trust in science and transparent communication are critical in reducing dependence on conspiracy beliefs. Strategies such as transparent government actions, fair policymaking, and proactive misinformation responses have been effective in countering perceptions of social instability and distrust in Australia [5]. Infographics explaining the scientific process have been shown to improve public confidence in science, indirectly decreasing susceptibility to misinformation [22]. Likewise, using altruistic messaging in vaccination campaigns—emphasizing the role of vaccines in protecting others—has led to increased vaccine uptake [4].

Memory-focused and cognitive strategies enhance the retention of accurate information while countering belief regression. Repeated corrections and encouraging deeper cognitive processing help individuals internalize accurate narratives, reducing the long-term effects of misinformation [23, 26]. Media literacy interventions that teach individuals to critically evaluate sensationalist health headlines have also been effective in lowering the spread and acceptance of misinformation [17].

Targeted interventions that address ideological divides and distrust in health institutions help strengthen adherence to public health measures. In Spain, reinforcing trust in health policies has contributed to increased vaccine acceptance [8]. Monitoring and countering conspiracy narratives in extremist online communities enable early intervention before misinformation escalates [25]. Providing accessible, evidence-based information has improved trust in healthcare systems, particularly among populations with historically low health literacy or high levels of skepticism [9].

These strategies work collectively to reduce fear, correct misinformation, and strengthen risk perception. By integrating community engagement, tailored communication, and transparent policymaking, these approaches mitigate conspiracy beliefs and promote trust in evidence-based healthcare practices [10, 27].

Evaluating the effectiveness of strategies against conspiracy beliefs

The effectiveness of these strategies varies. Some showed promise while others remain theoretical or untested. Early interventions in rumor control and algorithmic adjustments on platforms like Facebook reduced the reach of misinformation while increasing the visibility of accurate health messages, particularly during the Zika outbreak [14]. Two-sided refutational messages significantly improved pro-vaccination attitudes compared to exposure to misinformation alone [3]. Inoculation strategies also showed success, with targeted messaging in Hong Kong proving more effective in increasing vaccine intentions and positive attitudes than supportive messages alone [15].

Trust-building strategies produced mixed but encouraging results. Infographics explaining the scientific process contributed to a small yet significant increase in trust, indirectly reducing susceptibility to misinformation [22]. Transparent communication and scientific literacy initiatives enhanced vaccination rates and reduced skepticism, particularly in regions with strong extreme-right political alignment, such as Spain [8]. In Australia, fostering trust in government and addressing perceptions of social instability were associated with higher vaccine acceptance and lower endorsement of conspiracy theories [5]. Additionally, individuals who relied on credible sources, such as medical professionals, were 28% less likely to believe conspiracy theories, reinforcing the importance of trusted information channels [9].

Cognitive and analytical strategies also yielded measurable benefits. Memory-focused interventions, such as repeated corrections and deeper cognitive encoding of accurate information, accounted for 66% of the variance in belief regression, highlighting their effectiveness in reducing misinformation retention [26]. Analytical thinking interventions in the UK decreased susceptibility to misinformation while increasing trust in public health recommendations [12]. However, media literacy interventions had mixed outcomes; while they significantly reduced the intent to share inaccurate news, they also heightened skepticism toward accurate information [17].

Some strategies remain largely theoretical or require further evaluation. While community engagement, tailored communication, and interventions aimed at vulnerable populations are considered essential, they have not yet been widely assessed for effectiveness [2, 6, 10]. Theoretical frameworks, including the use of law enforcement and public health agencies to counter misinformation and extremism, require empirical validation to determine their practical impact [25].

Evidence-based approaches to countering conspiracy beliefs

The supporting evidence for strategies to mitigate conspiracy beliefs highlights their potential to counter misinformation and rebuild public trust. Community engagement and culturally tailored education have been identified as key interventions, emphasizing the importance of using alternative venues and culturally appropriate messaging to reach populations with high levels of mistrust [1, 2, 21]. Additionally, improving healthcare providers’ understanding of patient beliefs has been recommended to enhance communication and encourage compliance with public health measures [24].

The effectiveness of targeted messaging is demonstrated through initiatives such as the WHO’s “Dispelling Rumors Around Zika” campaign and Facebook’s efforts to amplify fact-checked information, which increased the visibility of accurate content while reducing the spread of misinformation [14]. Controlled experiments have further validated the impact of two-sided refutational messages in decreasing emotional resistance and improving attitudes toward vaccines. Meanwhile, web-based psychological screening has emerged as a promising approach to addressing conspiracy-related anxiety [3, 6].

Experimental studies support interventions such as inoculation messages, which strengthen resistance to misinformation by preemptively exposing individuals to flawed reasoning in conspiratorial narratives. A study in Hong Kong demonstrated that groups who receive inoculation messages showed significantly higher vaccine attitude scores than controls [15]. Similarly, randomized trials found substantial improvements in trust and vaccination intent when accurate information was combined with altruistic messaging, increasing vaccine willingness by 6.4% in the US and by 63.7% in the UK among those motivated by protecting others [4, 22].

Analytical thinking prompts and memory-focused strategies have been shown to reduce susceptibility to misinformation. Engaging individuals in active cognitive processing, such as careful reading and repetition of corrections, enhances information encoding and reduces belief regression over time [12, 26]. Media literacy interventions like News Tips decreased the intent to share inaccurate cancer-related news by 9% points, although findings from the BOAST intervention indicated the need for refinement, as it also increased skepticism toward accurate information [17].

Building trust in health authorities and ensuring transparency in public health communication have been linked to lower conspiracy belief scores, with each unit increase in trust corresponding to a 0.14 standard deviation decrease in conspiracy beliefs [8]. Efforts to engage with extreme-right political groups using transparency strategies have been identified as particularly effective in reducing skepticism and improving vaccination rates [27].

Stricter advertising guidelines and enhanced platform monitoring have been emphasized as necessary measures to limit the amplification of conspiracy narratives through external linking features and pseudo-scientific content. These strategies are essential for addressing the financial incentives that drive misinformation sharing on platforms such as Instagram [18, 25].

Discussion

This scoping review highlights the widespread prevalence of health-related conspiracy theories, which have been shaped by complex sociocultural, psychological, and political factors. Historical discrimination and systemic mistrust among racial and ethnic minorities contribute significantly to HIV-related conspiracy beliefs, directly impacting health behaviors and intervention efforts [1, 2]. In South Africa, conspiracy beliefs among adolescents are associated with skepticism toward biomedical prevention and treatment, emphasizing the need for culturally tailored educational programs to address misinformation [21]. The role of health beliefs and misinformation as key drivers of conspiracy endorsement further emphasizes the necessity of targeted interventions, particularly those addressing structural inequities [24]. As misinformation spreads, conspiracy theories do not remain static; they evolve in response to major crises, political shifts, and emerging health threats. Narratives from past public health crises, such as HIV/AIDS, are often repurposed and adapted to new contexts like the COVID-19 pandemic, fueling persistent mistrust and misinformation. This cyclical pattern reinforces skepticism toward healthcare systems and amplifies resistance to public health interventions.

Beyond fostering skepticism, conspiracy theories have substantial behavioral, psychological, and social consequences that hinder public health efforts. Exposure to conspiracy narratives reduces trust in health authorities, leading to lower vaccination intent and decreased engagement with preventive healthcare services [4, 11]. Additionally, conspiracy beliefs are linked to increased anxiety, depression, and vaccine hesitancy, further exacerbating their psychological toll [5, 7]. These mental health impacts can contribute to avoidance of healthcare services, reinforcing distrust in health institutions. Political ideology and social media play a role in amplifying misinformation, reinforcing ideological polarization, and resistance to public health measures [8, 13]. Marginalized populations, particularly those with lower socioeconomic status or limited health literacy, are disproportionately affected by these beliefs, creating significant barriers to accessing accurate health information and care [8, 13]. This highlights the inequitable burden of conspiracy theories on already vulnerable communities, further widening health disparities.

Digital platforms speed the dissemination of conspiracy theories, often outpacing verified health information. Misinformation on social media spreads widely due to algorithmic amplification, further fueling distrust in scientific expertise [6, 14]. The emotional appeal of conspiracy narratives, particularly those invoking anger and fear, enhances their persuasiveness and longevity [3]. These findings emphasize the need for proactive interventions, including content moderation, fact-checking initiatives, and regulatory measures such as misinformation flagging and improved content verification to complement educational strategies [18, 25].

While several strategies to mitigate conspiracy beliefs have been proposed, their effectiveness varies across different contexts. Inoculation messages and logic-based refutations have shown promise in countering misinformation, particularly in vaccine-related conspiracies [15, 23]. Repeated corrective messaging and efforts to build public trust in science contribute to reducing belief regression and misinformation acceptance [22, 26]. Among the interventions examined, inoculation messaging has shown the strongest evidence for improving vaccine-related attitudes in low-trust environments [17], whereas fact-based refutations were more effective at countering misinformation but had limited spillover protection against unrelated conspiracies [16]. Media literacy interventions showed mixed results; while they improved critical evaluation skills, they also heightened skepticism toward accurate health information [18]. This suggests that while each intervention has merit, their effectiveness depends on the sociopolitical context and target population. Addressing the social determinants of health, such as education, socioeconomic disparities, and cultural barriers, is critical in reducing the susceptibility of underserved populations to conspiracy theories [5, 27]. Interventions must account for these inequities to ensure that solutions are inclusive and equitable. However, interventions must be tailored to specific sociopolitical environments, as addressing ideological divides and promoting critical thinking are essential for combating misinformation effectively [10, 16]. Despite identifying multiple interventions to counter conspiracy beliefs, there remains a critical gap in comparative evaluations. No studies have directly compared the relative effectiveness of different countermeasures, making it difficult to determine which interventions work best in specific sociopolitical contexts or among different populations. This gap limits the ability to develop evidence-based, scalable solutions. Future research should prioritize head-to-head comparisons of intervention strategies, particularly in marginalized communities, where misinformation has the greatest impact.

In addition to existing interventions, several emerging strategies warrant further exploration in combating health conspiracy theories. Credibility labels, both peer-supplied and platform-driven, have been suggested as a means to enhance the visibility of accurate health information while reducing the reach of conspiracy-based misinformation [28, 29]. However, their long-term effectiveness remains uncertain, particularly among individuals already distrustful of authoritative sources. Research suggests that while credibility labels improve users’ ability to differentiate between reliable and unreliable health information, their overall impact on reducing conspiracy beliefs related to vaccines and public health policies is limited [28]. Automated content moderation, using artificial intelligence to detect and remove flagged misinformation, presents another promising but controversial approach. While AI-driven moderation can help curtail the spread of misleading health narratives, concerns remain regarding biases and potential over-censorship, particularly in discussions about vaccine safety, alternative treatments, or governmental public health measures [30]. Demonetization efforts, aimed at restricting revenue streams for conspiracy theorists and misinformation actors, have been introduced on some platforms, yet their effectiveness in curbing widespread conspiracy narratives remains uncertain. Many conspiracy networks adapt by migrating to alternative platforms or leveraging crowdfunding, limiting the long-term impact of demonetization [31]. Prebunking strategies, including gamification-based misinformation resistance, have shown promise in controlled settings by helping individuals develop cognitive resistance to misleading conspiracy claims [32]. Studies suggest that inoculation theory-based prebunking can be particularly effective in countering vaccine-related conspiracy theories and COVID-19 misinformation, but further research is needed to evaluate its adaptability across different sociopolitical and cultural contexts, particularly in marginalized communities where distrust in public health institutions is deeply rooted. While these emerging strategies offer potential solutions, their effectiveness in mitigating health conspiracy theories remains an open question, emphasizing the need for sustained, evidence-based interventions tailored to diverse populations.

Significant research gaps remain regarding the long-term effectiveness of counter-misinformation strategies. While the spread and impact of health-related conspiracy theories have been extensively documented, few studies have assessed the value of mitigation efforts. Many proposed interventions, including media literacy programs and trust-building initiatives, lack rigorous testing in diverse populations [9, 17]. Populations in underserved or resource-constrained settings are especially vulnerable, as conspiracy beliefs further hinder access to essential healthcare services, perpetuating public health disparities. Tackling these inequities requires sustained efforts to engage communities, build trust, and bridge gaps in healthcare access [5, 27]. The persistence of deep-seated mistrust, particularly among marginalized communities, complicates efforts to implement lasting solutions [5, 27]. Addressing these challenges requires a combination of evidence-based public health communication, community engagement, and digital regulation. Future research should prioritize large-scale, long-term studies to assess misinformation countermeasures and explore innovative methods to rebuild trust in health systems, particularly for vulnerable populations.

This review highlights the importance of culturally sensitive messaging, transparent health communication, and digital interventions in limiting the spread of misinformation. Future efforts should focus on evaluating the effectiveness of mitigation strategies and adapting them to different sociopolitical contexts. Policymakers, educators, and healthcare organizations can use these findings to develop interventions that strengthen public trust, improve media literacy, and enhance misinformation detection strategies across diverse communities.

Limitations

This study has several limitations. First, it relied exclusively on primary research articles published in peer-reviewed journals, which may have excluded valuable insights from gray literature, government reports, and expert analyses. Second, the review only included studies written in English, potentially missing important research conducted in non-English-speaking countries. Given the global nature of conspiracy theories, insights from other linguistic and cultural contexts could have provided a more comprehensive understanding of the issue. Third, while this review identified various interventions aimed at mitigating conspiracy beliefs, there was a lack of comparative studies on the effectiveness of different approaches across diverse populations. Without direct comparisons, it remains unclear which strategies are most effective in different sociopolitical and cultural settings, which limits the ability to provide concrete policy recommendations. Additionally, some interventions may have unintended consequences, such as reinforcing skepticism among certain groups or increasing resistance to corrective messaging. Fourth, many of the included studies relied on self-reported data, which may be subject to bias, including social desirability and recall inaccuracies. This is particularly relevant in studies examining sensitive topics such as mistrust in health authorities and vaccine hesitancy. Fifth, the role of algorithmic bias in amplifying misinformation on social media was not explicitly addressed in most studies. The selective exposure created by digital platforms may distort public perception and further entrench conspiracy beliefs, limiting the effectiveness of countermeasures. Sixth, most of the reviewed studies focused on Western and high-income countries, which may not fully capture the experiences of populations in low- and middle-income settings. Factors such as political instability, healthcare access, and historical distrust in government institutions vary across regions, making it essential for future research to examine how conspiracy beliefs manifest in different geopolitical contexts. Seventh, the review did not assess the long-term effectiveness of interventions designed to counter conspiracy beliefs. While some strategies, such as inoculation messages and media literacy programs, showed promise, there is limited evidence on their effectiveness over time. More longitudinal studies are needed to determine whether these interventions lead to lasting changes in attitudes and behaviors. Eighth, the impact of misinformation corrections on deeply entrenched beliefs remains uncertain. Some studies suggest that repeated exposure to debunking efforts may inadvertently reinforce false beliefs in certain groups, a phenomenon known as the “backfire effect.” This highlights the need for more nuanced research into the psychological mechanisms that shape misinformation retention and resistance to correction. Finally, while this review synthesized key findings on the spread and impact of health-related conspiracy theories, it did not analyze how these beliefs evolve over time, particularly in response to major events such as pandemics or political crises. Future research should explore the dynamic nature of conspiracy beliefs to develop more adaptive and effective strategies for countering them.

Conclusion

This scoping review highlights the pervasive and detrimental effects of conspiracy theories in the health sector. These theories, fueled by mistrust in governments, public health authorities, and scientific institutions, undermine critical health initiatives such as vaccination programs and compliance with public health measures. They thrive on misinformation, social media amplification, and emotional narratives, disproportionately impacting vulnerable groups, including those with lower socioeconomic status and limited health literacy. These inequities are particularly evident in marginalized communities, where historical injustices and systemic barriers exacerbate the harmful effects of conspiracy beliefs on access to care and health outcomes. The consequences of these theories emphasize the need for targeted interventions to address their root causes and mitigate their influence.

Actionable strategies must prioritize trust-building through transparency and consistent engagement with communities. Public health campaigns should leverage culturally relevant and emotionally resonant messaging to counter the appeal of conspiracy theories. Equally, educational initiatives aimed at improving media literacy and critical thinking can equip individuals to discern misinformation. Collaborative efforts between policymakers, healthcare professionals, educators, and social media platforms are essential to curb the dissemination of harmful narratives and promote accurate health information. Strengthening regulatory measures to counter misinformation while maintaining freedom of expression is another key policy consideration.

Moving forward, addressing health-related conspiracy theories requires a proactive and multifaceted approach. Investments in research to understand the psychological and social drivers of these beliefs can guide the design of more effective interventions. Additionally, acknowledging the challenges of intervention strategies, such as resistance to debunking efforts and the potential for unintended consequences, is crucial for refining future approaches. Integrating these insights into public health strategies will be pivotal in restoring trust, improving health outcomes, and building resilience against future waves of misinformation.

Recent policy shifts by major social media platforms have weakened misinformation moderation, exacerbating the challenge of combating health-related conspiracy theories. The divestment of content moderation teams by X (formerly Twitter), Meta’s reduced reliance on third-party fact-checkers, and Google’s rejection of the European Union’s (EU) fact-checking commitments contradict the findings of this review, which highlight the need for stronger regulatory oversight and proactive misinformation mitigation strategies [33]. The weakening of platform-driven countermeasures risks allowing conspiracy theories to spread unchecked, further undermining public trust in health communication. In response, alternative regulatory actions—such as the EU’s formalization of the Code of Practice on Disinformation under the Digital Services Act (DSA)—alongside independent initiatives led by non-governmental organizations (NGOs), educators, and researchers, will play an increasingly critical role in countering the impact of misinformation [34].

Future research should examine how conspiracy theories adapt to public health crises and evaluate real-time countermeasures to combat misinformation effectively. As social media policies increasingly allow unregulated misinformation to flourish, public health strategies must adapt by leveraging cross-sector collaborations, policy interventions, and community engagement efforts. Safeguarding communities against health conspiracy theories requires a proactive, evidence-based approach that integrates digital regulation, public trust-building, and global health resilience strategies.