Between- and Within-Person Associations Between Serum Lipids and Adolescent Depressive Symptoms

Cholesterol has previously been implicated in mental health outcomes but is less frequently studied during adolescence-a period of greater biological sensitivity and heightened risk for depression. In this study, 59 adolescents (ages 13-17) participated in two laboratory visits 3 months apart, during which they completed interviews to assess depressive symptoms and provided blood from which high-density lipoprotein (HDL) and low-density lipoprotein (LDL) were assayed. Multilevel models probed associations between depressive symptoms in relation to between-person and within-person differences in HDL and LDL above and beyond contributions associated with demographic characteristics. Results revealed that, across participants, higher levels of HDL and LDL were independently associated with higher depressive symptom scores. When considering associations within participants, higher levels of LDL relative to the participant's average were likewise associated with more depressive symptoms. Secondary analyses suggested that observed associations were largely not accounted for by BMI, waist-to-hip ratio, pubertal development, or physical activity. Taken together, this study provides preliminary evidence that cholesterol may be associated with depressive symptoms during an important period of development.