Effects of antidepressants on weight and on the plasma levels of leptin, TNF-alpha and soluble TNF receptors: A longitudinal study in patients treated with amitriptyline or paroxetine

Leptin, tumor necrosis factor-alpha (TNF-alpha), and soluble TNF receptors are involved in weight regulation. Antipsychotic agents, such as clozapine, induce weight gain and increase circulating levels of these cytokines. To assess whether obesity-inducing antidepressants have a similar effect, toe measured plasma cytokine levels in depressive inpatients during the first s ix weeks of treatment with tricyclic agents (amitriptyline or nortriptyline , n = 12), with paroxetine (n = 10), or without medication (n = 14). There was an increase in the body mass index at week 6 of treatment with the tric yclics, which was preceded by a significant increase in soluble TNF recepto r p75 plasma levels. Circulating levels of leptin were not affected. Paroxe tine and drug-free treatment did not affect any of these parameters. We con clude that weight gain induced by psychotropic agents may occur without inc reased circulating levels of leptin. However, activation of the TNF-alpha s ystem might be an early and sensitive marker of ensuing weight gain. [Neuro psychopharmacology 23:13-19, 2000] (C) 2000 American College of Neuropsycho pharmacology. Published by Elsevier Science Inc. All rights reserved.