Longitudinal assessment of clinical risk factors for depression in schizophrenia spectrum disorders

Abstract

Background: During initial assessment of individuals with schizophrenia and related disorders (schizophrenia spectrum disorders [SSDs]), clinicians tend to pay greater attention to psychotic symptoms than mood symptoms, including depression. Depression is reported to influence the course of SSDs, but not much is known about the risk factors for depression in SSDs. In the present study, we examined clinical predictors of depression in SSDs.

Methods: The sample included 71 patients with SSDs followed in a modified Assertive Community Treatment program, the Community Support Network of Springfield, Illinois. The study design was naturalistic, prospective, and longitudinal (mean follow-up = 8.3 years; SD = 7.3). The GENMOD procedure appropriate for repeated measures analysis with dichotomous outcome variables followed longitudinally was computed.

Results: Rates of depression ranged from 18% to 41% over the differing assessment periods. Schizophrenia and schizoaffective disorder did not vary by depression rate. Depression independent of SSD diagnosis was associated with greater hospitalization rates. Clinical variables predict- ing depression were auditory hallucinations, delusions, poor insight, and poor judgment.

Conclusions: Psychotic symptoms in the course of SSDs are risk factors for depression. As a consequence, the mental status examination of patients with SSDs with active psychosis should include assessment of mood changes. Further research is warranted to determine if treatment of depression among patients with SSDs may reduce their rates of hospitalization.