Depression is a common and often debilitating mental health condition. It has long been recognized for its profound impact on individuals’ well-being. Rates of depression have been increasing for years and in 2023 reached new highs. Recent research has unveiled a deeper connection between depression and physical health, shedding light on how metabolic impairment might play a role.
A study just published in JAMA Network Open, titled “Depressive Symptoms and Mortality Among US Adults,” has illuminated a critical aspect of depression that warrants our attention. This study, which examined a diverse and nationally representative sample of over 23,000 U.S. adults, revealed a striking association between depressive symptoms and mortality, particularly in the realms of cardiovascular disease and ischemic heart disease.
So, what does this study teach us about the relationship between depression and our metabolism?
First, it’s essential to understand that our brain is an energy-hungry organ. To function optimally, it requires a constant and stable supply of energy. When this energy supply is disrupted, the brain struggles to perform its functions effectively, and this can manifest as cognitive and emotional disturbances, including depression.
The study found that individuals with moderate to severe depressive symptoms faced a higher risk of all-cause mortality, cardiovascular disease mortality, and ischemic heart disease mortality. The numbers are compelling—people with moderate to severe depressive symptoms were 62% more likely to die early deaths. But what’s even more intriguing is how lifestyle factors come into play.
The study revealed that lifestyle factors may play a role in 11% to 16% of the association between depression and mortality. This opens a door to a vital conversation about how our daily choices, including our diets and physical activity levels, influence both our mental health and our physical well-being.
Depressive symptoms can be a sign that our brain’s metabolic processes are disrupted. For example, feelings of tiredness, low energy, changes in appetite, and loss of interest in activities are not just psychological markers of depression; they can also be indicators of underlying metabolic changes. These alterations may, in turn, affect our cardiovascular and overall health.
Metabolic impairment can lead to systemic inflammation, oxidative stress, and dysregulation of hormones like cortisol, all of which can contribute to the development of cardiovascular disease and other chronic conditions. In essence, depression may serve as a sentinel, alerting us to potential metabolic disruptions that could increase our vulnerability to mortality risk.
Metabolism is much more complicated than just diet and exercise. Many factors play a role, as I discussed in the post, “Brain Energy: The Metabolic Theory of Mental Illness.”
Understanding this link between depression, metabolism, and mortality opens up new avenues for intervention and prevention. It emphasizes the need for a comprehensive strategy to reduce the burden of depression. This strategy should not only focus on mental health treatment but also prioritize interventions, like lifestyle modifications, that support optimal brain energy metabolism.
Zhang Z, Jackson SL, Gillespie C, Merritt R, Yang Q. Depressive Symptoms and Mortality Among US Adults. JAMA Netw Open. 2023;6(10):e2337011. doi:10.1001/jamanetworkopen.2023.37011
Author’s Note: This post was originally featured on Psychology Today.
Christopher M. Palmer, M.D., is a Harvard psychiatrist and researcher working at the interface of metabolism and mental health. He is the director of the Department of Postgraduate and Continuing Education at McLean Hospital and an Assistant Professor of Psychiatry at Harvard Medical School.
