OBJECTIVES: The study examined (1) the role of experiential avoidance (EA), conceptualized as intolerance towards aversive mental states, in paranoid delusions and (2) the mechanisms underlying EA.

DESIGN: A 6-day prospective momentary assessment study.

METHODS: Paranoid patients (N = 41) were studied using the experience sampling method (ESM), a structured diary technique, assessing psychopathology and current context in daily life.

RESULTS: The results showed that both low self-esteem and EA contributed to paranoid thinking. The relationship between low self-esteem and paranoia was partially mediated by EA and the relationship between EA and paranoia was partially mediated by low self-esteem. The detrimental effect of EA on self-esteem was more pronounced under high activity-related stress. Both EA and social stress were independently associated with low self-esteem. EA was associated with self-esteem instability.

CONCLUSIONS: Our results implicate mental control strategies in the development of paranoia and are compatible with the attributional model of paranoia, which suggests that persecutory delusions arise as a result of dysfunctional attempts to avoid unpleasant thoughts about the self.

PRACTITIONER POINTS: Interventions for paranoid individuals should target low tolerance towards negative mental states, for example using mindfulness and ACT therapeutic approaches. Interventions designed for individuals suffering from persecutory delusions should also address unfavourable views about the self.

LIMITATIONS: Avoidance of unpleasant mental states may operate outside the individual's awareness and self-report measures of EA may be unable to adequately tap this process. Self-reflection abilities of psychotic patients may be impaired.