Low cholesterol is associated with depression among US household population

Serum cholesterol was reported to be associated with depressed mood, but the studies conducted among household population are rare.

We used the data of 4115 men and 4275 women aged 18 or older, who completed a depression screening interview and had blood collected as a part of the National Health and Nutrition Examination Survey, 2005-2008. The serum concentrations of total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were gender-specifically categorized into lower, intermediate, and upper quartiles. Depression was measured using the Patient Health Questionnaire, a 9-item screening instrument asking about the frequency of depression symptoms over the past 2 weeks.

After adjustment for socio-demographics and behavioral risks, a U-shaped association was detected between severe depression and LDL-C among men. The odds ratios (ORs) of severe depression were 5.13 (95% CI=1.74-15.09), 1 (reference) and 2.28 (1.07-4.86) respectively for the men with lower (<169 mg/dL), intermediate (169-221 mg/dL), and upper quartile (≥ 222 mg/dL) LDL-C. Among women, lower HDL-C was significantly associated with an elevated odds of severe depression [OR=2.96 (1.59-5.52)] compared with upper quartile of HDL-C, the association diminished after adjustment for covariates [OR=1.24 (0.66-2.32)]. No clear pattern of association between cholesterol and moderate depression was observed from either men or women.

The inherent limitation of cross-sectional design prevented the authors from investigating causality.

A U-shaped association was identified between LDL-C and severe depression among men. Further studies are necessary to explore the biological mechanism and identify the clinical implication among populations vulnerable to psychiatric disorders.