Psychotropic drugs in the treatment of obesity: what promise?

Obesity is a chronic and highly prevalent medical condition associated with increased risk for the development of numerous and sometimes fatal diseases. Despite its severity, there are few anti-obesity agents available on the market. Although psychotropic agents are not approved for the treatment of obesity, they have been used by clinicians as a therapeutic tool in daily clinical practice. The purpose of this article is to review the rationale, as well as the evidence, for the potential use of these agents in obesity treatment. Evidence for the efficacy of psychotropic agents in obesity treatment comes from different sources. The first type of evidence is weight loss observed with treatment in clinical trials of patients with neuropsychiatric syndromes (e.g. mood disorders, epilepsy). A recent example of such findings is the weight reduction reported in clinical trials involving obese patients with binge eating disorder. While randomised, controlled trials specifically designed to investigate the weight loss properties of psychotropic agents in obese patients are the most appropriate source of evidence of anti-obesity action, such trials remain scarce. The most studied psychotropic agents in obesity trials are drugs used in the treatment of mood disorders, i.e. mainly antidepressants and antiepileptics. SSRIs (e.g. fluoxetine, sertraline and fluvoxamine) were amongst the first psychotropic agents investigated in the treatment of obesity. Additional data have also been published for other antidepressants (e.g. venlafaxine, citalopram and bupropion) and antiepileptics (e.g. topiramate and zonisamide). Based on the available data for the efficacy of psychotropic agents in obesity and other related conditions, SSRIs may be considered for the management of certain subgroups of obese individuals with comorbid conditions such as depression, binge eating disorder and type 2 diabetes mellitus. In addition, some newer agents, such as bupropion, topiramate and zonisamide, appear to be promising candidates for selective use in the treatment of obesity. However, further studies are needed to define their possible role as new pharmacological options in the treatment of obesity.