B – 20 History of substance use differentiates patients and controls, but not across biotypes.

Abstract Objective The association between psychotic spectrum disorders and substance use disorders (SUD) has been widely documented. However, it remains unclear whether heterogeneity exists among subgroups of psychotic spectrum disorders regarding rates of SUDs. This study was designed to investigate the relationship between psychosis subgroups and substance use history. Method Archival data from the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP) consortium included 633 individuals diagnosed with a psychotic spectrum disorder, who were assigned a biotype based on key biological, cognitive, and behavioral measures, as well as 129 healthy controls. Participants were diagnosed based on semi – structured interviews for DSM-IV-TR, including detailed history of substance use. Biotypes 1 and 2 are characterized by cognitive impairment and we hypothesized that biotypes 1 and 2 would have a more extensive history of substance misuse than biotype 3 and healthy controls. Results A chi-square test of independence was conducted to examine the relationship between biotypes and substance use/dependence. Findings indicated a significant X2 (6, N = 762) = 91.9, p < .001, in which all biotypes had a history of more substance misuse compared to the healthy controls. However, there were no significant differences between the biotypes. Conclusions Findings indicated that all patient groups had a more extensive history of substance misuse compared healthy controls. Extensive and chronic substance misuse is often thought to contribute to the exacerbation of psychotic symptoms and cognitive dysfunction. However, the present pattern of findings suggests cognitive dysfunction in biotypes may be independent of substance use history.