Psychotropic drug induced weight gain: mechanisms and management.

Most of the drugs commonly used in the treatment and prophylaxis of depression, mania, and psychotic illness have, as one of their prominent side effects, the ability to increase appetite, stimulate carbohydrate craving, and promote weight gain. These side effects are troublesome to patients, and frequently constitute a major reason for premature discontinuation of therapy. This review examines the relative likelihood of the occurrence of appetite stimulation and weight gain with various psychotropic medications. Potential mechanisms of these effects and strategies to minimize or avoid weight gain during pharmacotherapy of psychiatric illness are examined. Evidence suggests that those compounds, which either antagonize or downregulate serotonin receptors, are more likely to stimulate carbohydrate hunger and weight gain. Amitriptyline, chlorpromazine, mesoridazine, thioridazine, and lithium are most likely to produce weight gain. Compounds that have more pronounced serotonergic action, such as fluoxetine and fenfluramine, are more likely to decrease carbohydrate craving and promote weight loss.