Differential prevalence of cigarette smoking in patients with schizophrenic vs mood disorders.

Rates of substance-use disorders among psychiatric patients are consistently higher than in the general population, yet there is no clear specificity to the relationship between types of substance use and psychiatric diagnoses. Cigarette smoking may represent a substance-use behavior which has greater specificity for major psychiatric diagnoses. We examined the self-reported history of cigarette smoking vs marijuana, alcohol and cocaine use among 83 male veteran psychiatric patients with primary mood (major depression or bipolar disorder; n = 20) or schizophrenic (schizophrenia or schizoaffective; n = 63) disorders. Those in the SCZ group compared to those in the AFF group were more likely to be ever-smokers (OR 8.5, 95% CI [2.2, 32.3]), and current smokers (OR 12.0%, 95% CI [3.6, 40]), independent of age differences between the groups. There were no significant differences in marijuana, alcohol or cocaine use between the two groups when age differences were controlled. Generalizability of the findings is limited by small number of subjects, male gender and veteran status; however, the significantly higher prevalence of smoking among individuals with schizophrenic disorders may support the growing evidence of linkages between the effects of nicotine and the neurobiology of schizophrenia.