Treatment of depression is often accompanied by weight changes. Previous studies indicate that leptin plays no role in this change despite showing a strong correlation with body mass index (BMI) in healthy people. The aim of this study was to evaluate the effect of imipramine and fluoxetine on BMI and its correlation with leptin. Eighteen depressed female patients randomly received either drug for 3 months. BMI was calculated and fasting blood samples were assayed for glucose, leptin, insulin, free fatty acids (FFA), and lipids. The difference between the changes in BMI (imipramine + 1.0 kg/m2, fluoxetine -0.5 kg/m2) was statistically significant (P < 0.05, t = 2.106). There was a significant positive correlation between overall BMI and leptin (r = 0.784, P < 0.001) but not between BMI and insulin or FFA. However, fasting insulin levels and calculated insulin resistance levels dropped substantially in the imipramine group. We conclude that the use of tricyclic antidepressants (TCAs) in depressed patients at risk for developing type 2 diabetes remains unresolved at this stage.