Relationship between tobacco and cannabis use status in outpatients with schizophrenia

Background and Objective While high prevalence of tobacco and cannabis use are well established in schizophrenia, reports on their co-morbid use is limited. We explored the links between tobacco and cannabis use in an outpatient population meeting DSM-IV criteria for schizophrenia. Methods Cigarette smoking behaviors were assessed in an outpaitent population with schizophrenia (N = 54) with current (n = 18), former (n = 24), and no lifetime cannabis dependence (n = 12). Results We found significant differences in cigarettes per day (CPD) across groups: current dependent patients smoked less CPD than patients with former dependence and those with no history of dependence; former dependent patients smoked significantly less than patients with no history of cannabis dependence. Conclusions and Scientific Significance Preliminary results support an effect of cannabis use status on tobacco consumption. In the absence of cannabis, patients may increase cigarette smoking, suggesting state-dependent effects of cannabis on tobacco. Prospective designs should further examine this relationship between cannabis and tobacco in schizophrenia versus non-psychiatric controls. (Am J Addict 2014;23:170-175)