Clinical Effects of Cannabis Use in First-Episode Acute Psychotic Patients

Cannabis is the most widely used illegal psychoactive substance worldwide. Although there are clinical studies examining the differences between psychotic symptoms emerging after cannabis use and non-cannabis-related psychotic symptoms, data are limited in the scientific literature. We aimed to investigate the effects of cannabis use on psychotic symptoms and compare the cognitive function differences between the cannabis-user and non-user groups.

First-episode psychotic patients were included in the study and divided into two groups based on cannabis use. Participants with cannabis use and without cannabis use were compared in terms of socio-demographic factors, psychotic symptoms, cognitive functions, and childhood trauma. All patients were assessed twice, during recruitment and after treatment for psychotic symptoms.

A total of 38 patients comprising of 18 patients with a history of cannabis use and 20 patients without a history of cannabis use were included. There were significant correlations between cannabis use, and living apart from family and family history of substance abuse. Negative psychotic symptoms were higher in the non-user group. The negative psychotic symptoms improved more significantly after treatment in the non-user group. There was a significant correlation between cannabis use and Stroop Color-Word Test scores.

Our results give us a chance to argue that psychosis has different features in people with and without a history of cannabis use. These two phenomena could differ in many ways, so different prevention strategies and treatment options should be considered.