Abstract
The aims of this study were to examine gender differences in symptoms, functioning, substance use problems and substance use correlates in patients with serious mental illness. The current study is cross-sectional, and data were collected using the Health of the Nation Outcome Scales for Severe Mental Illness (HoNOS-SMI) questionnaire. The questionnaire was completed by the patients' therapists. The study included 69 participants from a register of patients at a university hospital. Men had the highest HoNOS-SMI total scores (t = 2.918, df = 67, p = 0.005) with a Cohen's d = 0.72. We also found differences between men and women on several of the HoNOS-SMI subscores and items. In descending order, the strongest correlates for substance use problems for men were non-accidental self-injury (B = 0.770, SE = 0.327, β = 0.427, p = 0.027); problems with depressed mood (B = 268, SE = 0.171, β = 0.295, p = 0.131); and overactive, aggressive, disrupted or agitated behaviour (B = 0.44, SE = 0.204, β = 0.041, p = 0.829). The model as a whole accounted for 44.3% of the variance in the HoNOS-SMI item ‘Problem-drinking or drug-taking' and was significant [F (4, 25) = 4.961, p = 0.004]. For women, we found one significant correlation between the HoNOS-SMI item ‘Problem-drinking or drug-taking' and the HoNOS-SMI item ‘Problems with living conditions' (r = 0.481, p < 0.01). We found more severe symptoms and functional impairment, including substance use problems, among men. We also found several correlates of substance use for men, compared with only one for women.