Monoamine oxidase inhibitors and weight gain.

Weight gain associated with antidepressant therapy is a common problem that often results in noncompliance. Some authors suggest that monoamine oxidase inhibitors (MAOI) are less likely to produce weight gain than tricyclic antidepressants. This paper addresses the relative potential for weight gain with the MAOI. Assessing the potential for antidepressant-induced weight gain necessitates separating the weight changes associated with alterations in mood disorders from those due to drug-induced alterations in appetite control. The mechanisms of appetite control are reviewed briefly followed by proposed mechanisms by which the MAOI may alter this control. A literature review suggests that phenelzine is the MAOI most likely to induce weight gain; reports of isocarboxazid-induced weight gain are less common. There are no cases of tranylcypromine-induced weight gain in the literature that are clearly associated with the drug. The MAOI probably have different effects on the mechanisms of appetite control.