Caffeine, stress, and proneness to psychosis-like experiences

In diathesis-stress models of psychosis, cortisol released in response to stressors is proposed to play a role in the development of psychotic experiences. Individual differences in cortisol response to stressors are therefore likely to play a role in proneness to psychotic experiences. As caffeine has been found to increase cortisol response to a given stressor, we proposed that, when levels of stress were controlled for, caffeine intake would be related to hallucination-proneness and persecutory ideation. Caffeine intake, stress, hallucination-proneness and persecutory ideation were assessed by self-report questionnaires in a non-clinical sample (N = 219). Caffeine intake was positively related to stress levels and hallucination-proneness, but not persecutory ideation. When stress levels were controlled for, caffeine intake predicted levels of hallucination-proneness but not persecutory ideation. Implications of these findings are discussed and avenues for future research suggested.