Efficacy of aripiprazole as adjunctive therapy in major depressive disorder with somatic symptoms: A randomized, double-blind, placebo-controlled trial with clinical and electroencephalography evidence

Background: Somatic symptoms, which are common in major depressive disorder (MDD), are associated with a worse prognosis and increased health costs. Aims: This randomized, double-blind, placebo-controlled study evaluated the efficacy of aripiprazole augmentation in MDD patients with somatic symptoms. Methods: In all, 41 MDD patients with somatic symptoms completed the study. Participants who had been on a stable dose of antidepressants for at least 1 month were randomly assigned to receive an 8-week adjunctive treatment with either aripiprazole or placebo. The initiation dose of aripiprazole was 2 mg/day, which was later adjusted to 1–10 mg/day. The primary endpoint was the change in the Symptom Checklist-90-Revised-Somatization (SCL-90-R-SOM) score. We collected quantitative electroencephalogram data and performed spectral analyses to obtain the absolute power of frequency bands. Results/outcomes: The aripiprazole group ( n = 20; 2.98 ± 1.75 mg/day) showed a significant improvement in SCL-90-R-SOM scores compared to the placebo group ( n = 21; F = 8.56, p = 0.006), without significant differences in changes in depression and anxiety symptoms. Compared to the control, the aripiprazole group showed a greater decrease in total alpha power ( F = 7.03, p = 0.01). Changes in frontal alpha power were positively correlated with changes in SCL-90-R-SOM scores in the aripiprazole group ( r = 0.53, p = 0.014). Conclusions/interpretation: Aripiprazole adjunctive to antidepressants in patients with MDD and somatic symptoms improved somatic symptom severity without significant safety concerns, and this improvement correlated with a decrease in total and frontal alpha power. Trial Registration: https://cris.nih.go.kr ; identifier: KCT0004607.