Smoking Habits in Bipolar and Schizophrenic Outpatients in Southern Israel

Background: Although rates of cigarette smokinghave been found to be higher in schizophrenic and depressedpatients than in the general population, data regarding rates inbipolar patients are limited. This study further examines therelationship between bipolar disorder and smoking and comparesthe rate of smoking in bipolar disorder patients with rates inschizophrenic patients and in the general population.

Method: Seventy bipolar patients and 64schizophrenic patients (diagnosed using DSM-IV criteria) treatedat the largest specialized public bipolar and schizophreniaclinics in southern Israel were interviewed regarding theirsmoking habits. The interview included a questionnaire relatingto personal information, past and present smoking, and drug abuseand the Fagerstrom scale for nicotine dependence. Data from thesepatients were also compared with data from the general Israelipopulation.

Results: Data indicate that the rate of smokingdoes not appear to differ between bipolar (43.0%) andschizophrenic (45.0%) patients, whereas the rate for both patientgroups is higher than that for the general Israeli population(27.5%). Smoking intensity was not found to be different betweenthe 2 groups of patients.

Conclusion: Smoking in patients withschizophrenia was suggested to be related to nicotine cholinergicdysfunction, but this suggestion cannot explain the equally highrates of smoking in bipolar patients. Schizophrenia, bipolardisorder, and smoking may all be related to dopaminetransmission, and, therefore, dopaminergic interactions mayprovide a better explanation for the results.