Abstract
BACKGROUND: Vulnerability-stress models postulate that social stress triggers psychotic episodes in vulnerable individuals. However, experimental evidence for the proposed causal pathway is scarce and the translating mechanisms are insufficiently understood. The study assessed the impact of social exclusion on paranoid beliefs in a quasi-experimental design and investigated the role of emotion regulation (ER) as a vulnerability indicator and emotional responses as a putative translating mechanism. METHODS: Participants fulfilling criteria for clinical high risk of psychosis (CHR, n = 25), controls with anxiety disorders (AC, n = 40), and healthy controls (HC, n = 40) were assessed for dysfunctional (eg, rumination, catastrophizing, blaming) and functional ER-strategies (eg, reappraising, accepting, refocusing). They were then exposed to social exclusion during a virtual ball game (Cyberball) and assessed for changes in self-reported emotions and paranoid beliefs. RESULTS: The CHR sample showed a significantly stronger increase in paranoid beliefs from before to after the social exclusion than both control groups. This was accounted for by lower levels of functional and higher levels of dysfunctional ER (compared to HC) and by a stronger increase in self-reported negative emotion in the CHR group (compared to AC and HC). CONCLUSIONS: The results confirm the role of negative emotion on the pathway from social stressors to psychotic symptoms and indicate that both the use of dysfunctional ER strategies and difficulties in employing functional strategies add to explaining why people at risk of psychosis respond to a social stressor with increased paranoia.