There appears to be a back-and-forth link between depression and obesity, say researchers who reviewed the findings of 15 studies that included nearly 59 000 people.
"We found bidirectional associations between depression and obesity: obese persons had a 55% increased risk of developing depression over time, whereas depressed persons had a 58% increased risk of becoming obese," wrote Dr Floriana S. Luppino, of Leiden University Medical Centre in the Netherlands, and colleagues.
Further analyses found that the link between obesity and later depression was stronger among Americans than among Europeans, and stronger among people diagnosed with depression than in those with depression symptoms.
There are a number of theories about how obesity and depression may be linked, the researchers said:
Obesity may be considered an inflammatory condition and inflammation is associated with risk of depression.
Thinness is a beauty ideal in both Europe and the United States, so being overweight or obese may contribute to body dissatisfaction and low self-esteem that increases the risk of depression.
Depression may play a role in weight gain through interference with the endocrine system or due to adverse effects of antidepressant drugs.
The findings, published in the Archives of General Psychiatry, can help improve patient care, the researchers said.
"Because weight gain appears to be a late consequence of depression, care providers should be aware that within depressive patients weight should be monitored," they said. "In overweight or obese patients, mood should be monitored. This awareness could lead to prevention, early detection and co-treatment for the ones at risk, which could ultimately reduce the burden of both conditions." - (HealthDay News, March 2010)