Clinical evidence continues to reveal a close relationship between chronic depression and declining physical health, specifically that caused by increased body fat. A recent study found that levels of depression among its middle-aged female subject group correlated very closely with the amount of visceral fat inside their bodies. It would appear that the metabolic and lifestyle changes common to long-term depression encourage the accumulation of excess adipose tissue. The conclusion is not exactly new, but the study’s results clarify an important distinction between the fat types and their effects on the body.
Subcutaneous fat is located directly below the skin, and it’s more immediately visible than its visceral cousin. But the fat that accumulates beneath the abdomen and along the waistline does more long-term damage. As fat to body mass ratios increase, this tissue eventually impedes the internal organs, significantly heightening subjects’ chances of developing diabetes and various cardiovascular diseases. It slows metabolism rates and prevents the body from efficiently processing food.
The group in the most recent study question was relatively homogeneous: middle-aged Caucasian and African-American women participating in a longitudinal menopause survey on the South side of Chicago. This uniformity allowed researchers to more accurately measure the effects of mental illness on physical health. Even after controlling for central variables like age, race, lifestyle and general health status, researchers found that the amount of visceral fat in each woman’s body, as measured by CT scan, corresponded very closely with their reported levels of depression. And their depressive symptoms were not caused by negative body images or sedentary lifestyles: the chicken apparently came before the egg in this case.
Researchers speculate that depression encourages weight gain by lowering internal levels of the stress hormone cortisol, which grows too active to effectively replenish itself after moments of anxiety. Cortisol also regulates metabolism and blood pressure and acts to break down fatty acids. In combination with the social withdrawal and inactive lifestyle that often accompany long-term depression, these hormonal changes allow the visceral fat to pool and interfere with the functions of the internal body systems. The serious physical risks related to long-term depression only serve to emphasize the importance of effective treatment. If left unchecked, its ultimate consequences could be much worse than a higher BMI.