The May 7 article "Polypharmacy: Too Much of a Good Thing?" describes a study that compares hospitalized patients on antipsychotic polytherapy with hospitalized patients on antipsychotic monotherapy. Since this study found no difference in outcome between these two groups, both Psychiatric News and the authors of the study speculated that antipsychotic polytherapy is unwarranted.

The patients in the polytherapy group were matched carefully. However, as both articles acknowledged, patients in the polytherapy may have been more treatment resistant than patients in the monotherapy group. Patients in the polytherapy group had an earlier onset of illness. Also, they might not have responded as well to an initial antipsychotic in their outpatient and/or inpatient treatment. Why else would psychiatrists have given them more than one antipsychotic at the same time?

If patients in the polytherapy group were more treatment resistant than patients in the monotherapy group, then a different explanation is required for this study. Specifically, a better explanation would be that the treatment-resistant patients in the polytherapy group needed an additional antipsychotic to reach the same therapeutic level as the patients in the monotherapy group. Rather than conclude that polytherapy is unwarranted, we might then speculate that many treatment-resistant patients need to be given more than one antipsychotic to reach the same therapeutic level as less treatment-resistant patients.

Despite the need for controlled studies, which both articles acknowledged, the obvious emphasis in both articles is on the potential futility of polytherapy rather than on the potential need for polytherapy for treatment-resistant patients. I believe that this bias is unwarranted.