This study examined the prevalence of cigarette smoking and the quantity of cigarettes consumed by individuals with schizophrenia or bipolar disorder and by those with no psychiatric disorder in the period 1999–2011.
A total of 991 individuals with schizophrenia, bipolar disorder, or no psychiatric illness provided information about their cigarette smoking at recruitment into a research study for which they were selected without regard to their smoking status. Differences among groups and trends over time among new enrollees were examined with multivariate models. Regression analyses were used to compare smoking between the schizophrenia and bipolar disorder groups.
There were marked differences in the prevalence of smoking and in the quantity of cigarettes consumed among the diagnostic groups. Overall, 64% of individuals with schizophrenia, 44% with bipolar disorder, and 19% without psychiatric illness reported that they were current smokers. These group differences remained fairly constant over the observation period, and there were no statistically significant time trends in smoking or cigarette consumption after adjustment for demographic covariates. Within the psychiatric illness groups, smoking and cigarette consumption were significantly associated with less education, a history of substance abuse, longer illness duration, Caucasian race, and schizophrenia diagnosis but not with psychiatric symptom severity.
The prevalence of smoking has remained alarmingly high among individuals with schizophrenia and bipolar disorder in routine psychiatric settings. Concerted efforts are urgently needed to promote smoking cessation in these groups.