This is a precarious situation for depressed individuals, because they are more likely to incorporate these messages into their body image, putting themselves at risk for developing an eating disorder. A negative body image is a central feature of eating disorders. Since depression is known to cause a negative body image, it is important to study its relation to eating disorders. The link between eating disorders and depression is inconclusive. Many common depressive features such as depressed mood, irritability, low energy, and low concentration have been reported in studies of the physical and psychological effects of semi-starvation .
Some psychologists argue that eating disorders represent a variant or masked form of depression.
Over short periods of time, underweight patients with anorexia nervosa tend to show improvements in their depressive symptoms with weight gain and nutritional stabilization. However, a small number of long term follow up study suggest that a disproportionate number of patients show signs of depression at follow up. Although these studies are indecisive, they suggest new options in treating depression and eating disorders. Some psychologists have suggested that treating depression may involve addressing body image issues, whereas eating disorders may respond to treatment with anti-depressants. Biological markers have also been investigated in order to gain insight into the relationship between depression and eating disorders.