Depression; schizophrenia; antipsychotics; antidepressants; anti-inflammatory agents; biomarkers

Depressive symptoms may occur in any phase of schizophrenia and can have far-reaching consequences. Areas covered: The author focuses on recent reviews and meta-analyses dealing with the prevalence, importance, etiopathogenesis, and pharmacotherapy of comorbid depression and schizophrenia. Depressive symptoms in acute episodes may improve in parallel with psychosis due to antipsychotic treatment. Therefore, the first step is to evaluate the current antipsychotic treatment of psychotic symptoms and consider changing the dosage. A second step is switching antipsychotic medications, since there are indications that some medications are slightly more effective in reducing depressive symptoms than others. For persistent depressive episodes, additional therapeutic interventions are indicated. Most guidelines recommend the administration of antidepressants as an add-on treatment with a limited evidence level. Immunotherapeutic strategies could be successful, at least in some schizophrenia patients. Expert opinion: In the near future, precision psychiatry should enable clinicians to recognize specific biotypes with unique biosignatures that will guide accurate and prompt clinical management for individual patients.