OBJECTIVES: The aim of this study was to investigate serum leptin, adiponectin and paraoxonase1 levels in adult females receiving pharmacotherapy for various psychiatric disorders. METHODS: The study group consisted of 32 obese females (mean age 40.53 +/- 11.00 years, mean body mass index 35.44 +/- 5.33 kg/m(2)) who were receiving treatment for psychiatric disorders, and the control group included 22 obese females (mean age 35.95 +/- 9.16 years, mean body mass index 30.78 +/- 3.33 kg/m(2)) who were free of psychiatric disorders. Analyses were performed using a bioelectrical impedance device. Fasting blood samples were obtained for complete blood count and various biochemical tests, including determination of leptin, adiponectin and paraoxonase1 activity. RESULTS: Body mass index, waist and hip circumference, body fat percentage, fasting blood glucose, insulin, glycosylated hemoglobin, homeostasis model assesement of insulin resistance, alanine transaminase, aspartate tarnsaminase, and leptin levels were significantly higher in the study group than in controls. Although body weight was positively correlated with leptin levels in both groups, body weight was negatively correlated with adiponectin levels in the control group and positively correlated with adiponectin levels in the study group. In the study group, body mass index and hip circumference correlated positively with leptin levels, hip circumference correlated positively with adiponectin levels, and waist to hip ratio correlated positively with paraoxonase levels. In the control group, body mass index as well as waist and hip circumferences were positively correlated with leptin levels. Weight, body mass index, and hip circumference were also negatively correlated with the adiponectin/leptin ratio in the control group. CONCLUSION: This study indicates a higher risk for obesity-related disorders, particularly metabolic syndrome, diabetes and cardiovascular disease, in patients treated with psychiatric drugs.