The burden of depressive symptoms in the long-term treatment of patients with schizophrenia

Abstract

Objective To prospectively measure the link between depressive symptoms and functional outcomes in the long-term treatment of people with schizophrenia. Methods Data were drawn from a large, multi-site, 3-year, prospective, naturalistic, observational study, in which subjects with schizophrenia were assessed at enrollment and at 12-month intervals thereafter. Individuals who were “Depressed” (defined as a total score ≥ 16 on the Montgomery–Asberg Depression Rating Scale) at enrollment were compared to those “Non-depressed” on functional outcomes, using self-report measures, clinicians' ratings, and information from medical records. Statistical analyses included Generalized Estimation Equation and mixed regression analyses adjusted for individual characteristics. Longitudinal group comparisons across the 3-year study were augmented with a cross-sectional group comparison at enrollment. Results At enrollment, 39.4% (877/2228) of the participants were deemed Depressed. Across the 3-year study, the depressed cohort was significantly more likely than the Non-depressed to use relapse-related mental health services (emergency psychiatric services, sessions with psychiatrists); to be a safety concern (violent, arrested, victimized, suicidal); to have greater substance-related problems; and to report poorer life satisfaction, quality of life, mental functioning, family relationships, and medication adherence. Furthermore, changes in depressed status were associated with changes in functional outcomes. Conclusions People with schizophrenia and concurrent depressive symptoms have poorer long-term functional outcomes compared to the Non-depressed. Their poorer quality of life, greater use of mental health services, and higher risk of involvement with law enforcement agencies underscore a need for special treatment interventions. Treatment of the non-psychotic dimensions of schizophrenia is a critical part of recovery.