Relationship of Serum Lipid Profiles and Serotonin with Major Depression: A matched case-control study

Background: several studies have explored the relationship between blood lipid levels and depressive disorders. Specific studies reported an association between lower serum cholesterol and depressive disorder, while some other studies no connection. The aim of this study was to evaluate the relationship of serum lipid profiles and serum serotonin with depressive disorder. Methods: In the present study, the total serum cholesterol, LDL-C, HDL-C and serum serotonin of 45 patients with depressive disorder as a case group, and 45 normal people without depressive disorder as a control group was measured. Age, sex, weight and height were matched in both groups. Diagnosis of depression was conducted by using both the Beck and Hamilton depression Rating scale, followed by an interview by a psychiatrist. Results: The LDL-C serum concentrations of the case group was higher than the control group (121.1±30.9 vs107.9±36.9; P<0.1); moreover, the HDL-C serum of the case group was significantly lower than the control group (52.6±11.9 vs. 34.4±9; p<0.0001). The Serum serotonin of case group was higher than the control group, but this difference was not statistically significant (455.9±393 vs. 418.1±224.4).The total cholesterol and TG of case group were higher than control group, but these differences were not statistically significant (178±37.8 vs. 191.2±47 and 127.4±56.2 vs. 148.5±88.4 respectively). Conclusions: The Serum HDL-C concentration of depressed patients was significantly lower than the control group, suggesting a possible convers relationship between serum HDL-C and Depression. The serum LDL-C concentration of depressed patients was also higher than the controls showing a possible relationship. However there was no statistical significant difference between the total serum cholesterol, triglyceride and serum serotonin between two groups.