Antidepressant medicines have been shown to be effective for patients suffering from major depression, but less than one-third of the 16 million Americans with the condition benefit from the first antidepressant they’re prescribed.

If a depressed patient is not improving after a month or so, the doctor often switches to a different antidepressant because these medicines vary in their effectiveness with individual patients.

However, a new study of more than 1,500 depression patients at 35 Veterans Health Administration medical centers suggests there may be a more effective strategy for medication-resistant patients.

Researchers found that adding an antipsychotic medicine or a second antidepressant to the mix may be more helpful than switching to another antidepressant drug altogether.

Dr. Somaia Mohamed and her collaborators at Yale University found that nearly a third of patients who took the antipsychotic drug aripiprazole (Abilify) or the antidepressant bupropion (Wellbutrin) along with their original antidepressant achieved nearly total remission after three months.