Clinical Edge

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Cigarette smoking a risk factor for schizophrenia

Key clinical point: Cigarette smoking is associated with an increased risk of developing schizophrenia and non-affective psychosis.

Major finding: In men, incidence rates for schizophrenia per 100000 person years were higher in smoking initiators (adjusted incidence rate ratio [aIRR], 1.94) and smokers (aIRR, 3.32) vs nonsmokers. In women, incidences were higher in smokers (aIRR, 1.50) but not higher in smoking initiators vs nonsmokers. For non-affective psychosis, the pattern was similar for men but more evident in women where incidences were higher in smoking initiators (aIRR, 1.90) and in smokers (aIRR 2.13) vs non-smokers.

Study details: Observational study of 907,586 participants (aged 15–24 years) using data from The Health Improvement Network primary care database, UK between 2004 and 2009.

Disclosures: No study sponsor was identified. The authors declared no conflicts of interest.


King M et al. Psychol Med. 2020 Mar 9. doi: 10.1017/S0033291720000136.