Bipolar Disorder and disorders of the Bipolar Spectrum (BD) are, globally, the sixth leading cause of disability (Woods, 2000). 20-50% of BD subjects endorse some form of cannabis-related problems (Cerullo and Strakowski, 2007) with a recent study reporting higher severity of illness and greater treatment non-compliance in chronic cannabis users (van, I et al. 2009). While there has been a considerable amount of interest – and controversy – surrounding the associations between cannabis use and (variously defined) “psychosis” (Hall and Degenhardt 2000; Macleod et al., 2007), a recent study shows only a modest reduction in the association between cannabis use and mania when excluding psychotic features (Henquet et al., 2006). However, prior studies that have examined the association between cannabis-related behaviors and BD are characterized by several limitations including low sample size, limited assessments of BD and also limited data on comorbid conditions. We (a) report on the association between lifetime cannabis use and BD; (b) examine patterns of cannabis involvement in those with BD and (c) investigate BD-related outcomes in those with comorbid cannabis use disorders.
