Abstract
BACKGROUND: Subsyndromal symptoms of depression (SSD) in patients with schizophrenia are common and clinically important. While treatment of depression in major depressive disorder may partially ameliorate cognitive deficits, the cognitive effects of antidepressant medications in patients with schizophrenia or schizoaffective disorder and SSD are unknown. METHODS: The goal of this study was to assess the impact of SSD and their treatment on cognition in participants with schizophrenia or schizoaffective disorder aged ≥40 years. Participants were randomly assigned to a flexible dose treatment with citalopram or placebo augmentation of their current medication for 12 weeks. An ANCOVA compared improvement in the cognitive composite scores, and a linear model determined the moderation of cognition on treatment effects based on the Hamilton Depression Rating Scale and the Calgary Depression Rating Scale scores between treatment groups. RESULTS: There were no differences between the citalopram and placebo groups in changes in cognition. Baseline cognitive status did not moderate antidepressant treatment response. CONCLUSIONS: Although there are other cogent reasons why SSD in schizophrenia warrant direct intervention, treatment does not substantially affect the level of cognitive functioning. Given the effects of cognitive deficits associated with schizophrenia on functional disability, there remains an ongoing need to identify effective means of directly ameliorating them.