Sex difference in the prevalence of smoking in Chinese schizophrenia

Despite a large proportion of smoker in Chinese population, few studies address the prevalence of smoking in schizophrenia in such a homogeneous ethnic group. This study examined gender-specific relationships between smoking and schizophrenia, which have previously received little systematic study. The prevalence of smoking in 510 inpatients with schizophrenia and 793 normal controls was evaluated. The relationships between smoking and retrospectively assessed measures of the course of schizophrenia were evaluated by clinician-administered questionnaires. The results showed that the gender difference in smoking prevalence was in the opposite direction for males compared to females between schizophrenia and normal controls. Male patients had a higher smoking rate than controls (81% vs 66%, adjusted OR = 2.3, p < 0.0001), while female patients had a lower rate than controls (5% vs 9% p > 0.05). Smoking was associated with a family history of smoking, a personal history of alcohol use and age in men with schizophrenia. Our present findings suggest a significant gender difference in the prevalence of smoking in schizophrenia.