Longitudinal changes in cognitive biases mediate the association between stress exposure and psychotic-like...

Exposure to stress is a well-established risk factor for psychotic experiences, yet the cognitive mechanisms underlying this association remain insufficiently understood. This study examined whether longitudinal changes in cognitive biases mediate the relationship between stress exposure and changes in psychotic-like experiences (PLEs) in the general population sample of adults aged 18-40 years.

Adults without a history of psychiatric treatment were assessed at baseline and at 12-month follow-up. Change-score mediation models with bootstrap confidence intervals were estimated, adjusting for age, gender, and education.

Of 5,126 adults who completed the baseline assessment, 2,290 (44.7%) participated in the follow-up. Greater stress exposure predicted increases in PLEs, negative, and depressive symptoms. After correction for multiple testing, significant indirect effects consistent with mediation by cognitive biases were observed for PLEs, but not for negative or depressive symptoms. These effects were significant for changes in belief inflexibility, safety behaviors, external attribution, and subjective cognitive and social cognitive problems, but not for attention to threat or jumping to conclusions. Reverse mediation models indicated consistently smaller indirect effects. In parallel multiple-mediator models, no individual bias showed a unique indirect effect on PLEs, yet the total indirect effect remained significant, suggesting mediation through interrelated biases. Social cognitive problems emerged as the only bias with a specific indirect effect on negative and depressive symptoms.

Longitudinal changes in cognitive biases might represent an indirect pathway to the association between stress exposure and increases in PLEs. These findings highlight cognitive biases as potential targets for preventive interventions.