Abstract
This study examines demographic and attitudinal determinants of belief in COVID-19 conspiracy beliefs in Poland and their impact on psychological well-being, social functioning, and adherence to public health measures over one year. A cross-sectional study with a retrospective component was conducted one year after the pandemic outbreak (N = 1000). A COVID-19 conspiracy belief factor, extracted via PCA, served as the dependent variable in hierarchical regression models. Changes in P-score (psychological distress), S-score (social functioning), WHO-5 score (well-being), and adherence to public health guidance were analyzed using t-tests. Key predictors of conspiracy belief included lower education, younger age, higher religiosity, and distrust in experts. Conspiracy believers (CTB) exhibited significantly higher P-scores (greater psychological distress) compared to non-believers (N-CTB). While S-score (social functioning) and WHO-5 score (well-being) declined in both groups over time, differences between CTB and N-CTB were not significant. Stronger conspiracy beliefs were associated with lower adherence to public health guidelines from the pandemic's outset, with no significant improvement after one year. These findings confirm previous research linking conspiracy beliefs to reduced adherence to health measures and poorer psychological outcomes. However, they challenge assumptions that conspiracy beliefs necessarily impair well-being and social functioning over time. Strengthening institutional trust and addressing misinformation remain critical for improving public health compliance.