Insulin Resistance and Major Depressive Disorders: Insights from Stanford University Study
Study Overview
A recent investigation conducted by Stanford University indicates that insulin resistance may play a significant role in the onset of major depressive disorders. This emerging connection could pave the way for more effective treatment and prevention strategies for individuals suffering from depression. Currently, depressive disorders rank as the leading cause of disability globally.
Symptoms of Depression
Individuals experiencing depression often exhibit a range of symptoms, including persistent sadness, lethargy, loss of appetite, and difficulty sleeping. Natalie Rasgon, co-author of the study, stated, “If you’re insulin-resistant, your risk of developing major depressive disorder is double that of someone who’s not insulin-resistant, even if you’ve never experienced depression before.”
Understanding Insulin Resistance
Insulin resistance refers to a condition where cells in the body become less responsive to insulin, a hormone that facilitates the uptake of glucose (sugar) into cells for energy or storage. Factors contributing to insulin resistance include lifestyle choices that can impair the insulin-cell communication, such as overindulgence in food and a lack of physical activity.
Research Findings on Insulin Resistance and Depression
Association Between Markers
The Stanford research team utilized data from the Netherlands Study of Depression and Anxiety, which has been tracking over 3,000 participants for nearly a decade. They focused on a subset of 601 individuals aged 18-65, all of whom had no prior history of anxiety or depressive disorders. Key indicators of insulin resistance, including waist circumference, fasting blood glucose levels, and the triglyceride to HDL ratio, were examined.
The study revealed a correlation between these markers and the onset of major depressive disorder. Specifically, for every 5cm increase in abdominal fat, there was an 11% rise in the likelihood of developing depression. Furthermore, an increase of 18mg/dL in fasting blood glucose levels was associated with a 37% increase in depression onset.
Link Between Prediabetes and Depression
After two years, the research highlighted that the emergence of prediabetes, a form of insulin resistance, was linked to the development of major depressive disorder. Participants who transitioned to prediabetes within this timeframe had a 2.66 times higher risk of developing major depressive disorder by the ninth year of the study.
Implications for Healthcare
Natalie Rasgon emphasized the need for healthcare professionals to consider metabolic conditions such as prediabetes and diabetes when assessing mental health disorders. She advocated for a combined approach to understanding insulin resistance and depression, which could lead to new treatment and prevention avenues. “To prevent depression, physicians should be checking their patients’ insulin sensitivity. These tests are readily available in labs around the world, and they’re not expensive. In the end, we can mitigate the development of lifelong debilitating diseases.”
Future Directions
Ongoing research may further elucidate the relationship between insulin resistance and the emergence of major depressive disorders, potentially influencing future treatment protocols and preventative measures.
References
Watson, K. T. et al. (2021). Incident Major Depressive Disorder Predicted by three Measures of Insulin Resistance: A Dutch Cohort Study. The American Journal of Psychiatry. Doi: 10.1176/appi.ajp.2021.20101479.
Friedrich, M.J. (2017). Depression is the leading cause of disability around the world. JAMA; 317(15): 1517. Doi: 10.1001/jama.2017.3826.
Goldman, B. (2021). Insulin resistance doubles risk of major depressive disorder, Stanford study finds. EurekAlert! Accessed Oct. 1, 2021. Retrieved from https://www.eurekalert.org/news-releases/928847.