According to the results of a systematic review published in The British Journal of Psychiatry, limited evidence indicates that antidepressants may treat depression effectively in patients with comorbid schizophrenia.
To determine the effectiveness of antidepressants for depression in patients with schizophrenia, researchers reviewed 26 studies of antidepressant use in patients with schizophrenia or related psychosis and depression. They evaluated the effectiveness of individual antidepressants and antidepressant classes with meta-analyses that assessed response to antidepressant therapy and improvement in follow-up depression score.
Antidepressant use was shown to be effective based on binary data from 8 studies that classified patients as responders or nonresponders at the study endpoint (summary risk difference -0.19). The number needed to treat was 5.
In a random-effects meta-analysis of 17 studies, antidepressant treatment improved endpoint depression score significantly (standard mean difference -0.24). The study authors noted, however, that removal of one small study with a large effect size resulted in a nonsignificant treatment effect (standard mean difference -0.20).
Meta-analysis of antidepressant classes and of citalopram individually did not yield statistically significant effects on depression scores.
The study authors explained that the study, “produced some evidence in favour of antidepressant treatment for depression in schizophrenia.” They noted, however, that, “a lack of rigorous reporting of adverse outcomes in included trials in this review prevented calculation of number needed to harm, and caution must be taken when recommending pharmacological interventions and the avoidance of unnecessary polypharmacy.”
Gregory A, Mallikarjun P, Upthegrove R. Treatment of depression in schizophrenia: systematic review and meta-analysis. Br J Psychiatry. 2017;211(4):198-204.