Kraus et al. (2001) recorded lower leptin levels and normal BMI for MDD patients compared to healthy controls, but this leptin reduction did not depend on whether or not the patients had been treated using psychotropic medication during the past 4 weeks. In contrast, Esel et al. (2005) found that leptin levels were higher both before and after the response to antidepressant treatment, with further elevation on the leptin levels after the improvement from depression with antidepressant treatment. The gene discussed is LEP; the disease is depressive disorder.