Depression reduces physical activity and sometimes promotes food intake, which increases the risk of obesity. Duloxetine is an antidepression drug produced by Eli Lily that works by blocking the breakdown of serotonin and norepinephrine in the brain.
A Canadian study on rats fed a high-fat diet (HFD) showed that duloxetine promoted weight loss as well as the weight loss drug sibutramine (Meridia). The rats consumed the diet for five weeks and increased weight by 17.57 percent and food intake by 57.15 percent, compared to normal animals. Obese animals were treated with duloxetine and sibutramine for four weeks or duloxetine alone.
Duloxetine was as effective as sibutramine in reducing food intake, bodyweight, and body fat, and increasing metabolic rate (fat burning). Duloxetine decreased blood pressure, while sibutramine increased it. Duloxetine also improved symptoms of depression and increased physical activity levels. The study showed that depression might be an important factor in obesity and that treating it might promote weight loss. (Canadian Journal Physiology and Pharmacology, 87: 900-907)