Categorical variables were

compared using Pearson’s chi-square test and Fisher’s exact test. Correlations between variables were tested using Pearson and Spearman correlation coefficients. A p-value < 0.05 was considered as significant. Bonferroni correction was used for multiple comparisons. Results Demographic findings and laboratory results of study groups are given in Table 1. Clinical characteristics Inhibitors,research,lifescience,medical of MDD patients are given in Table 2. There were no significant differences in age, sex distribution and body mass indices (BMI) between the study groups. In the MDD group 14 patients (35%) had their first depressive episode and never used antidepressants; whereas 20 patients (50%) had their second and 6 patients (15%) had their third depressive episodes. Table 1. Demographic findings and laboratory Inhibitors,research,lifescience,medical results of patients with major depressive disorder and the control group. Table 2. Clinical characteristics of major depressive disorder patients. There was no significant difference between patient and control groups in terms of serum they levels of BDNF, VEGF and leptin. There was also no difference between these parameters when compared according to sex. There was no correlation between BDNF and VEGF levels Inhibitors,research,lifescience,medical in terms of age and BMI in both groups. There was no statistical difference between BDNF levels of suicidal depressive patients, nonsuicidal depressive patients and controls. The number of depressive

episodes and BDNF levels Inhibitors,research,lifescience,medical were found to be negatively correlated (r = -0.390, p = 0.017) (Figure 1). VEGF levels were negatively correlated with HDRS scores (r = -0.326, p = 0.043) in the patient group. Figure 1. Comparison of serum BDNF levels in first episode and recurrent depressive patients. Serum leptin levels correlated positively with BMI in both groups (r = 0.416, p = 0.009). Leptin levels were significantly higher in women in the control group (p = 0.030), but no such difference was observed in the patient group. Leptin levels Inhibitors,research,lifescience,medical correlated positively with triglyceride, very low density lipoprotein and insulin levels in the patient group

(p < 0.01); no such relation was present in control group. There was no difference between cortisol levels in patient and control groups and leptin was not found to be correlated with cortisol. There was no correlation between leptin levels and HDRS scores, number of depressive episodes or suicidality in the patient group. Discussion In the present study, there were no significant Drug_discovery differences between melancholic depressive patient and control groups in terms of serum BDNF, VEGF and leptin levels. However, BDNF levels were found to be negatively correlated with the number of depressive episodes. In addition, VEGF levels were found to be negatively correlated with increased severity of depression. To our knowledge this study is the first to have investigated serum BDNF, VEGF and leptin levels in purely melancholic depressive patients.