Adding Antidepressants to Antipsychotics for Treatment of Subsyndromal Depressive Symptoms in Schizophrenia: Impact on Positive and Negative Symptoms

Objectives: It remains unclear how augmenting anti-psychotic medications with anti-depressants impacts primary positive and negative symptoms of schizophrenia. In this study, we used data collected from a randomized trial comparing citalopram to placebo for management of subsyndromal depression (SSD) in schizophrenia and schizoaffective disorder, to assess the effects of antidepressant augmentation on positive and negative symptoms. Materials and Methods: Participants in this study conducted at the University of California, San Diego and the University of Cincinnati, were persons with schizophrenia or schizoaffective disorder aged 40 or older and who met study criteria for SSD. Patients were randomly assigned to flexible-dose treatment with citalopram or placebo augmentation of their current anti-psychotic medication. Analysis of covariance was used to compare changes in positive and negative syndrome scale (PANSS) scores between treatment groups. We also assessed mediating effects of improvement in depression and moderating effects of multiple factors on positive and negative symptoms. Results: There was significant improvement in PANSS negative symptoms scores in the citalopram group, which was partially mediated by improvement in depressive symptoms. There was no effect on PANSS positive scores. Conclusions: In patients with schizophrenia/schizoaffective disorder, treating depressive symptoms with citalopram appears to carry the added benefit of improving negative symptoms.