The findings, published in the Journal of Clinical Psychiatry, add to evidence that people receiving "real" depression treatment in studies -- from antidepressants to St. John's wort -- often do no better than people given a placebo.

A recent review found that a minority of antidepressant users even fared worse than placebo users.

In this latest study, researchers randomly assigned 156 depression patients to either take the antidepressant sertraline (Zoloft and other brands) daily for 16 weeks; undergo a form of psychotherapy called supportive-expressive therapy (twice a week for four weeks, then weekly for 12 weeks); or be in a placebo group given inactive pills.

After 16 weeks, there were no overall differences in how the three groups fared.

Of antidepressant patients, 31 percent were treatment "responders" (meaning they'd fallen below a certain score on a standard measure of depression symptoms, or had seen their score drop at least 50 percent.)

The same was true of about 28 percent of patients in the talk-therapy group, and 24 percent in the placebo group. The differences among the three groups were so small as to be likely due to chance.