Effectiveness of a video-based intervention for COVID-19 vaccine acceptance among individuals with mental disorders : a randomized online experiment

Abstract

Introduction: During the COVID-19 pandemic, vaccine hesitancy and low risk awareness were also observed in high-risk groups, such as individuals with mental disorders. This study evaluated an educational video aimed at increasing COVID-19 vaccine acceptance in this population.

Methods: A randomized online experiment with 639 participants from the German general population (MAge = 37.04; 77.8% female; 24.4% self-reporting a mental disorder) was conducted during the second year of vaccine distribution. Participants were randomly assigned to either the educational video or a control group (no video). Outcomes included vaccination willingness, threat perceptions, and vaccine-specific beliefs. Moderation analyses examined differential effects for diagnostic status and internalizing psychopathology.

Results: The intervention significantly increased awareness of the importance of vaccination for individuals with mental disorders (p = 0.033, d = 0.17), perceived severity of COVID-19 (p = 0.010, d = 0.21), and deliberative decision-making (p = 0.015, d = 0.19). However, it did not significantly increase vaccination willingness or change vaccine-specific beliefs. Moderation analyses showed that participants with a self-reported mental disorder had greater perceived susceptibility (p = 0.032, d = 0.36), but internalizing psychopathology did not influence outcomes.

Discussion: While the video improved awareness and threat perceptions, further efforts are needed to address vaccine hesitancy and motivate behavior change in high-risk populations.