Jones Fernyhough 2009 Caffeine, Stress, and Proneness to Psychosis-Like Experiences

Personality and Individual Differences 46 (2009) 562–564

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Short Communication

Caffeine, stress, and proneness to psychosis-like experiences: A preliminary investigation
Simon R. Jones *, Charles Fernyhough
Department of Psychology, Durham University, South Road, Durham DH1 3LE, UK

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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 hallucinationproneness, 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. Ó 2008 Published by Elsevier Ltd.

Article history: Received 8 July 2008 Received in revised form 15 October 2008 Accepted 31 October 2008 Available online 19 December 2008 Keywords: Coffee Hallucination Persecutory ideation Psychosis Schizophrenia Tea

1. Introduction Diathesis–stress models of psychosis propose that stress may play a contributory role in the development of hallucinations and delusions, typically associated with the schizotypal/schizophrenia spectrum (Neuchterlein & Dawson, 1986). Cortisol has been

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