Adjunctive Brexpiprazole in Major Depressive Disorder with Inadequate Response to Antidepressants: A Prospective Study

Background: This study evaluated the effects, safety, and tolerability of adjunctive brexpiprazole in adult patients with Major Depressive Disorder (MDD) who experienced an inadequate response to antidepressant monotherapy. Methods: This 12-week, multicenter, naturalistic, prospective observational study enrolled 60 adults with MDD and inadequate response to two or more antidepressant treatments who were prescribed adjunctive brexpiprazole. Outcomes in depressive symptoms, anxiety symptoms, illness severity, psychosocial functioning, and quality of life were assessed using the Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), Clinical Global Impressions–Severity (CGI-S), Clinical Global Impressions–Improvement (CGI-I), Sheehan Disability Scale (SDS), and World Health Organization Quality of Life–Brief Version (WHOQOL-BREF). Results: Fifty participants completed the week 12 assessment. Mean PHQ-9 scores decreased from 16.68 ± 5.64 at baseline to 11.50 ± 7.30 at week 12 (p < 0.001), and mean GAD-7 scores decreased from 13.32 ± 4.98 to 9.80 ± 5.63 (p < 0.001). At week 12, PHQ-9 response and remission rates were 38.0% and 22.0%, respectively; corresponding GAD-7 rates were 34.0% and 14.0%. Mean CGI-S scores decreased from 5.00 ± 1.16 to 3.52 ± 1.79 (p < 0.001); the mean week 12 CGI-I score was 2.44 ± 1.22. Mean overall SDS scores decreased from 16.00 ± 7.27 to 11.44 ± 8.36 (p < 0.001), with improvements across all domains. Conclusions: In clinical practice, adjunctive brexpiprazole was associated with early improvement in depressive and anxiety symptoms, illness severity, psychosocial functioning, and quality-of-life domains.