Is there a role for leptin in the reduction of depression symptoms during weight loss therapy in obese adolescent girls and boys?

Several studies have sought to clarify the association between adolescent obesity and psychological distress. Recently, a biological link between leptin resistance and depression has been proposed. The aim of the present study was to examine changes in leptin concentrations as a potential predictor of reduced depression symptoms in obese adolescents during long-term interdisciplinary weight loss therapy. Seventy-five obese adolescents (age: 16.28 ± 2.37 years; BMI: 35.65 ± 4.64 kg/m2) engaged in a long-term interdisciplinary therapy for weight loss. They were evaluated at baseline and after 1 year of treatment for body composition, serum analyses and depression symptomatology. After therapy, body mass BMI, fat mass (% and kg), waist circumference, visceral, subcutaneous and visceral/subcutaneous fat and depression symptoms decreased and lean mass (%) increased significantly. There was an improvement in inflammatory profiles with a significant reduction in leptin and increase in adiponectin. Regression analyses showed that decreased leptin predicted amelioration in depression symptoms independent of age, gender and changes in visceral fat, body mass, fat mass (%) and leptin/adiponectin ratio. These associations appear stronger in girls than boys. The attenuation of hyperleptinemia appears to play an important role in the association between weight loss and depression, particularly in obese girls.