Treatment of subsyndromal depressive symptoms in middle-aged and older adults with schizophrenia: effect on functioning.

BACKGROUND Subsyndromal symptoms of depression (SSD) in patients with schizophrenia are common and clinically important. SSRI's appear to be helpful in alleviating depressive symptoms in patients with schizophrenia who have SSD in patients age 40 and greater. It is not known whether SSRI's help improve functioning in this population. We hypothesized that treating this population with the SSRI citalopram would lead to improvements in social, mental and physical functioning as well as improvements in medication management and quality of life. METHODS Participants were 198 adults > or = 40 years old with schizophrenia or schizoaffective disorder who met study criteria for subsyndromal depression based on having two or more of the nine DSM-IV symptoms of a major depressive episode, for at least 2 weeks, and a Hamilton depression rating scale (HAM-D 17) score > or = 8. Patients were randomly assigned to flexible-dose treatment with citalopram or placebo augmentation of their current antipsychotic medication(s) which was stable for 1 month. Subjects were assessed with the following functional scales at baseline and at the end of the 12-week trial: (1) social skills performance assessment (SSPA), (2) medication management ability assessment (MMAA), (3) mental and physical components of the medical outcomes study SF-12 Scale, and (4) the Heinrichs quality of life scale (QOLS). Analysis of covariance (ANCOVA) was used to compare differences between endpoint scores of the citalopram and placebo treated groups, controlling for site and baseline scores. ANCOVAs were also used to compare differences in the above endpoint scores in responders versus non-responders (responders = those with > 50% reduction in depressive symptoms). RESULTS Overall, the citalopram group had significantly higher SSPA, mental functioning SF-12, and quality of life scale (QOLS) scores compared to the placebo group. There was no effect on MMAA or physical functioning SF-12 scores. Responders had significantly better endpoint mental SF-12 and QOLS scores compared to non-responders. Response to citalopram in terms of depressive symptoms mediated the effect of citalopram on mental functioning, but not on the quality of life. CONCLUSIONS Citalopram augmentation of antipsychotic treatment in middle aged and older patients with schizophrenia and subsyndromal depression appears to improve social and mental health functioning as well as quality of life. Thus it is important for clinicians to monitor these aspects of functioning when treating this population of patients with schizophrenia with SSRI agents.