Predictors of antidepressant response

The development of new pharmacological agents has dramatically improved the treatment of major depressive disorders. But the question of whether there are reliable predictors of response to a particular agent or class of agent remains to be answered completely. The author provides an overview of current understanding of antidepressant response prediction in terms of three sources of variance: clinical variables, biological variables, and pharmacological response. He also notes evidence of the effectiveness of two nonpharmacological treatments, sleep deprivation therapy and light therapy.