Eating disorders are not depressive disorders.
Eating disorders are physical disorders associated with psychological factors and are a common category of psychosomatic disorders in psychosomatic medicine; whereas depression is a mood disorder. The similarities between the two are that both can present with somatic abnormalities such as loss of appetite, reduced eating, weight loss and poor mood.
However, people with depression do not have an overwhelming fear of weight gain compared to those with eating disorders, and are also characterised by depressed mood, lack of pleasantness, slowed thinking, reduced volitional activity, low self-esteem, pessimism, self-blame and sleep disturbances.
In addition, and very importantly, depressed people’s eating less behaviour is often secondary to depressed mood and reduced activity.
The two are therefore very different.