Tobacco Use Moderates Associations Between Cannabis Use, Psychiatric Symptoms, and Cognitive Performance in Psychosis Spectrum Disorders

Authors:
Preprint
Publisher website
Google Scholar
Abstract
Tobacco and cannabis use are highly prevalent among individuals with psychotic disorders. Tobacco use has been consistently linked to poorer clinical and cognitive outcomes, whereas findings regarding cannabis use remain mixed. The present study leveraged a large multi-site psychosis spectrum sample with comprehensive cognitive and clinical assessments to more precisely characterize how tobacco or cannabis use, co-use, and non-use differentially relate to function. The final sample included 323 healthy controls and 884 individuals with psychotic disorders. Individuals with psychosis, regardless of substance use status, exhibited significantly worse cognitive performance across cognitive domains compared to healthy individuals. Among individuals with psychosis, exclusive tobacco use was associated with the highest symptom burden and the greatest cognitive impairment. In contrast, cannabis use showed more nuanced associations. Greater cannabis use was tied to worse general psychosis symptoms for current tobacco users but fewer general symptoms for those who never used tobacco. Further, more cannabis use was linked to better cognitive performance for current tobacco users but was not linked to working memory for prior users of tobacco. Taken together, these findings highlight tobacco use as a potential marker of greater disease severity and cognitive impairment among individuals with psychosis, while also demonstrating the importance of considering patterns of co-occurring use of substances such as cannabis.