 Six hundred and eighty-one patients with severe chronic depression (some with other psychiatric illnesses) were enrolled in the trial, and were assigned to either Serzone, CBASP, or combination Serzone-CBASP for 12 weeks.The response rates to either Serzone or CBASP alone were 55 percent and 52 percent, respectively, for the 76 percent who completed the study.In other words, a little more than half of the completers in those two arms of the trial reduced their depression by 50 percent or better.