Risk of hospitalization among patients with co-occurring psychotic and substance use disorders: a 12-year follow-up

Aim. The study aims to analyze the impact of substance use disorders (SUD) on the risk of hospitalization among patients affected by psychotic disorders. Methods. During 1995, the patients consecutively admitted to psychiatric hospitalization or to an outpatient visit, were included in the study. Patients were interviewed by a questionnaire with specific reference to Addiction Severity Index (ASI), in order to assess the presence of SUD. During 2008, for each patient, the retrospective assessment of the days and the number of hospitalizations, due to psychiatric cause between 1996 and 2007, was performed. Results. During 1995, 102 patients were included in the study, 15 patients (14.7%) with a current SUD, 17 patients (16.7%) with a past SUD, and 70 patients (68.6% of the sample) without SUD. The follow-up analysis did not show any statistically significant difference among the three subgroups for what concerns the risk of receiving at least one hospitalization and the risk of involuntary treatment. By contrast, hospitalized patients with current SUD, if compared to hospitalized patients with past SUD or patients without SUD, appeared to have a significantly higher overall number of hospital admissions and days of hospitalization. Discussion. The current SUD group showed, in terms of hospitalizations, worse prognostic profiles than the group without SUD and the group with past SUD. The prominent role of a comprehensive assessment and a therapeutic strategy taking into account the potential negative effect of substance use on the stabilization of psychotic symptoms is therefore confirmed.