Substance Use in Patients With First-Episode Psychosis: Is Gender Relevant?

Only a few studies in patients with first-episode psychosis have included gender in the study hypothesis or considered this a primary study variable. The aim of this study was to explore the influence of gender in the pattern of substance use in patients with first-episode psychosis.

This is a sub-analysis of a randomized open clinical trial that compared 1-year treatment retention rates of patients with first-episode psychosis randomized to haloperidol, olanzapine, quetiapine, risperidone, or ziprasidone. Our sub-analysis included 85 men and 29 women.

Substance use was relatively high among these patients and differed significantly by gender. Men were more likely to use substances overall than women (89.4% for men vs. 55.2% for women), χ(2) = 16.2, df = 1, p <.001, and were also more likely to use alcohol (χ(2) = 13, df = 1, p <.001), cannabis (χ(2) = 9.9; df = 1, p <.002), and cocaine (χ(2) = 10.3; df = 1, p <.001), compared to women. While there were no gender differences in age at first consumption of alcohol or cocaine, men were significantly younger at first consumption of cannabis (M = 16.08 years, SD = 2.1) than women (M = 18.0 years, SD = 3.8), F(1, 59) = 5, p <.02. When analyzed separately by gender, women showed no significant differences in the influence of number of substances used on age at onset of psychosis, F(3, 29) = 1.2, p =.30. However, there was a significant difference among men, with earlier onset of psychosis noted in men consuming multiple substances; F(4, 85) = 5.8, p <.0001. Regarding prediction of age at onset of psychosis, both male gender and the use of a higher number of substances significantly predicted an earlier age at onset of psychosis.

Our study provides some evidence of gender differences in the pattern of substance use in patients with first-episode psychosis, suggesting the possible need for gender-specific approaches in the interventions performed in these patients. This study is registered as #12610000954022 with the Australian New Zealand Clinical Trials Registry (www.anzctr.org.au).