Course, remission and recovery in patients with severe psychotic disorders with or without comorbid substance use disorders: Long-term outcome in evidence-based integrated care (ACCESS II study)

OBJECTIVES: People with psychotic disorders have a high prevalence of comorbid mental disorders, especially if severe mental illness (SMI) criteria are fulfilled. Substance Use Disorders (SUD) are the most common comorbidity. The aim of the study is to investigate whether SMI patients with and without comorbid SUD have a comparable course, remission and recovery rates within evidence-based care.

METHODS: ACCESS is an integrated care model for patients with severe nonaffective and affective psychotic disorders. Treatment trajectories of patients, who have been in ACCESS care for at least 4 years, with and without SUD were compared with regard to the course of illness using Mixed Model Repeated Measures (MMRM) as well as recovery rates and its predictors.

RESULTS: 187 of 312 patients (60%) were at least 4 years in ACCESS. Of these, 126 (67.4%) had a comorbid SUD at admission. Patients had on average 2.96 SUD, 87 (69%) had a dependence. Both groups improved significantly over 4 years in all outcome parameters. However, patients with substance dependence showed significantly worse outcomes in psychopathology (p < 0.001), functioning (p = 0.006) and quality of life (p = 0.026). Using LOCF, 44 patients (23.5%) fulfilled recovery criteria at endpoint. Comorbid substance use dependence was the only significant predictor for non-recovery (OR = 0.462, p = 0.048).

CONCLUSION: SUD and especially substance dependence are common in psychotic disorders with SMI. Evidence-based integrated care also leads to long-term improvement in these patients, but to a lesser extent than in patients without SUD. In particular, the "optimal" outcome recovery is made more difficult by SUD dependence.