Trazodone is a new antidepressant agent that was recently introduced in the United States. It has a unique pharmacological profile that is not typical of either tricyclic or monoamine oxidase inhibitor antidepressants. As such it represents a new class of antidepressant drugs. The efficacy of trazodone has been clearly established in comparative studies with imipramine and amitriptyline. Major depression is the principal indication for its use, but good results have been shown in a wide variety of depressive subtypes. Of particular importance is the low frequency of adverse reactions seen with this drug.