Lorcaserin in Obesity: Identification of CNS Targets Using fMRI

The purpose of this protocol is to investigate the effect of treatment with the study drug, called lorcaserin on centers of the brain that control appetite and food intake, as well as lorcaserin's other metabolic effects. Lorcaserin's effect on the brain will be investigated using functional magnetic resonance imaging (fMRI). Lorcaserin was approved in June 2012 as an addition to a reduced-calorie diet and exercise, for chronic weight management. Previous weight loss drugs, such as fenfluramine, acted throughout the body and caused heart problems. Lorcaserin is different because it only acts on receptors (sites of action) that are found in the brain and does not act on the heart, and thus, has not been shown to cause the heart problems seen in the past. 1. To examine the effects of the study drug lorcaserin, on the brain, and its impact on food visualization (high fat and low fat images) and interaction with satiety (by measuring during the fasting or fed states) using fMRI. (Satiety is defined as when a person has had enough or too much food and does not want to eat any more, as after finishing a satisfying meal.) 2. To examine the satiety and weight-reducing effect of lorcaserin using physiological measurements (such as how much weight is lost and how this may affect hormone levels), and its association with changes in fMRI responses and neuropsychological performance. To examine whether the long-term weight reducing effects of lorcaserin can be predicted by early food visualization.