Tobacco use before, at, and after first-episode psychosis: A systematic meta-analysis

Objective: Patients with first-episode psychosis have a high prevalence of tobacco use. We aimed to examine the prevalence and course of tobacco use during early psychosis using meta-analysis. Data Sources: Systematic search of MEDLINE (1948-2011), Embase (1947-2011), CINAHL (1984-2011), PsycINFO (1967-2011), and ISI Web of Science (1900-2011) using the search terms [psychosis OR schizophrenia] AND [tobacco OR smoking OR nicotine]. Study Selection: We located 10 studies reporting the age at initiation of daily tobacco use and the age at onset of psychosis, 31 studies reporting prevalence of tobacco use in patients with first-episode psychosis, 10 studies comparing smoking to age-/gender-matched controls, and 7 studies reporting prevalence of tobacco use at intervals after treatment. Data Extraction: The following data were extracted: age at initiation of daily tobacco use and at onset of psychosis, the proportion of patients with first-episode psychosis who used tobacco, the proportion of the general population who used tobacco, and the proportion of patients with psychosis who used tobacco at various intervals after initiation of antipsychotic treatment. Results: The pooled estimate for the interval between initiation of tobacco use and the onset of psychosis was 5.3 years (standardized mean difference = 0.85). The estimated prevalence of tobacco users in first episode of psychosis is 58.9% (95% CI, 54.3%-63.4%). There is a strong association between first-episode psychosis and tobacco use (OR = 6.04; 95% CI, 3.03-12.02) compared with healthy controls. The prevalence of tobacco use at intervals between 6 and 120 months after treatment remained unchanged (OR = 0.996; 95% CI, 0.907-1.094). Conclusions: Patients with first-episode psychosis tend to have smoked for some years prior to the onset of psychosis, have high prevalence of tobacco use at the time of presenting for treatment, and are much more likely to smoke than aged-matched controls. Their apparent difficulty in quitting has implications for tobacco cessation programs and efforts to reduce cardiovascular disease among people with mental illness.