Brexpiprazole is known to act as a partial agonist at 5-HT1A receptors and D2 receptors, and previous studies suggest this mechanism may help reduce aggression in animals. In the current study, Maurizio Fava, M.D. (pictured left), a professor of psychiatry at Harvard Medical School, and colleagues recruited 54 adult patients aged 18 to 65 with MDD and irritability who failed to respond adequately (as documented by a self-report of a less than 50% response) to their antidepressant treatments for two weeks. The patients received six weeks of open-label treatment with their current antidepressant regimen and adjunctive brexpiprazole (ranging from 1 mg to 3 mg daily). After six weeks, brexpiprazole was discontinued, and patients continued treatment with antidepressants alone for an additional four weeks.
Outcome measures included changes in depression, irritability, and anger from baseline to week 6 and from week 6 to week 10. Multiple rating scales were used to assess outcome measures, including the Montgomery-Asberg Depression Rating Scale, the Sheehan Irritability Scale, and the Kellner Symptom Questionnaire.
At week 6, clinically relevant improvements were observed in irritability, anger, and depressive symptoms. However, no further improvements in irritability, anger, and depressive symptoms were observed after brexpiprazole was discontinued at six weeks. Overall, adjunctive brexpiprazole was well tolerated with no clinically meaningful changes from baseline to endpoint in mean fasting metabolic parameters.
“Adjunctive treatment with brexpiprazole may represent a strategy for the treatment of irritability symptoms in patients with MDD and inadequate response to antidepressant treatment,” the authors wrote. “[W]hether these effects are reproducible in a placebo-controlled study needs to be confirmed,” they concluded.
For related information, see the Psychiatric News article “Brexpiprazole Found Safe for Patients With Schizophrenia.”
(Photo Courtesy of Harvard Medical School)