Insulin resistance, the loss of response of peripheral insulin receptors to insulin, is known to be a risk factor for major depressive disorder. In this study, the authors explored the relationship of insulin resistance to the presence, severity, and chronicity of major depression in 1269 individuals with current MDD, remitted MDD, and no history of MDD. Insulin resistance was found to correlate with current MDD as well as severity and chronicity of depressive episodes. The results indicate that insulin resistance may be a state biomarker for depression. These data suggest that measures of insulin resistance used in this study, including the quantitative insulin sensitivity check (QUICKI) as well as the triglyceride to high-density lipoprotein (HDL) ratio, may be easily employed to augment assessment of patients with MDD.
Watson KT et al. JAMAPsychiatry 2020; Epub ahead of print. Abstract