St. Louis—For more than half of older adults, an antidepressant alone isn’t enough to resolve their depression. A new study, published online by The Lancet, however, finds that those patients often can be successfully treated by adding a second drug—an antipsychotic medication. Washington University School of Medicine researchers studied 468 adults older than 60 years who had been diagnosed with depression, touted as the largest trial of its kind for that age group with depression. Study participants received an extended-release formulation of the antidepressant drug venlafaxine, marketed as Effexor XR, for 12 weeks. Aout half of these patients remained clinically depressed and, in the second phase of the study, continued to receive venlafaxine in combination with aripiprazole, marketed as Abilify, or a placebo. The two-drug combination led to a remission of depression in 44%of the treatment-resistant patients, compared with only 29% of those who had received the placebo, according to the results.