Smoking among psychiatric outpatients: relationship to substance use, diagnosis, and illness severity.

To understand the elevated smoking rates among psychiatric patients, the authors investigated whether psychiatric diagnosis, illness severity, and other substance use predicted smoking status in a diverse sample (N=2774) of psychiatric outpatients. Results indicated that 61% smoked daily and that 18% smoked heavily. Smoking was related to psychiatric diagnosis and illness severity as well as caffeine consumption and substance abuse. Diagnoses of bipolar disorder, schizoaffective disorder, and schizophrenia were independently related to smoking status, an association that was most pronounced among persons treated at clinics serving more impaired patients. Thus, diagnosis and illness severity contribute to elevated smoking rates, even after controlling for other substance use. Cessation programs are needed to reduce tobacco use in this vulnerable population.