Contagions of Doubt: Denialism and the Spread of Medical Conspiracy Theories

Denialism and conspiratorial thinking have long shaped public perceptions of science and medicine, but the COVID-19 pandemic exposed how rapidly these forces can evolve and spread in a digital age. This thesis examines the historical roots, psychological foundations, and modern amplification of medical conspiracy theories, with a particular focus on vaccine skepticism and COVID-19-related misinformation. As a literature review, it synthesizes existing interdisciplinary research from psychology, public health, and communication studies to explore how medical conspiracy beliefs emerge from complex interactions between cognitive biases, emotional needs, mistrust in institutions, and evolving media environments. The rise of social media, political polarization, and foreign disinformation campaigns further intensified the spread of conspiracy narratives during the COVID-19 pandemic, undermining public health efforts. In response, this thesis highlights emerging strategies such as prebunking, media literacy initiatives, and trust-building communication as critical tools for mitigating the influence of medical conspiracy theories. The findings underscore the necessity of a multifaceted approach that addresses both individual vulnerabilities and systemic drivers of misinformation, while also identifying key areas for future research to better prepare for upcoming public health challenges.