Outcome of patients with dual diagnosis in secondary psychiatric care

Dual diagnosis (DD) is a common co-morbidity of mental illness and substance use disorder (SUD) and patients with DD are prone to complications. Better knowledge on the outcome, mortality and management of patients with DD in usual secondary psychiatric care would help to inform improved treatment strategies in the future.

To explore the functional outcome and mortality of patients with DD receiving psychiatric treatment. To assess the recognition of substance use disorders (SUDs) in terms of diagnosis, and the associations of clinically diagnosed SUDs with treatment-related variables.

The sample of 330 patients was collected by screening all currently treated patients with the Alcohol Use Disorders Identification Test (AUDIT) and a question about other substances used. The inclusion criteria were AUDIT >7 and/or reported use of other substances during the preceding 12 months. The Global Assessment of Functioning scale was used to assess functional outcomes during a 2-year follow-up. Information concerning treatment and patient characteristics was collected retrospectively.

Level of functioning remained stable among all study patients during follow-up. The mortality rate was not increased. Effective medication use was associated with improved functional outcomes. SUDs were underdiagnosed. A clinically diagnosed SUD seemed to have an impact on the regularity of appointments and the doses of prescribed medications.

Given our results suggesting a stable level of functioning, patients with DD appear to be well managed within secondary psychiatric care. Attention should be paid to more precise diagnostics of SUDs and to effective use of medication.