This paper reviews the literature on the physiological causes of bulimia and investigates the rationale behind the usage of antidepressant medication in the treatment of bulimia nervosa. No definite conclusions can be stated regarding the physiology of bulimia, but a number of hypotheses are suggested. It appears that the hypothalamus is involved in bulimia nervosa, and that endorphins related to obesity are also apparent. The literature further hypothesizes that the satiety function is impaired in bulimics, and that serotonin and norepinephrine levels are also impaired. The treatment of bulimia nervosa with tricyclic antidepressants remains controversial. These drugs work with many people, but the reasons why they work remain somewhat unclear. One hypothesis states that major depression may be associated with a lack of activity of norepinephrine in the brain, and that serotonin may also be involved in major depression. Both of these neurotransmitters have been implicated as being dysfunctional in bulimics, leading to the hypothesis that bulimia and mood disorders are somehow related. Chemotherapy as an effective treatment modality for bulimia should remain under investigation. It is hypothesized that desipramine will be effective in reducing the bingeing and purging behaviors of bulimics, and that an adequate blood level needs to be reached before desipramine produces its desired effects. If this hypothesis proves to be valid, it will add to the support that chemotherapy is a viable treatment option for bulimia, that bulimia may somehow be linked with affective disorder, and that bulimia may have a physiological basis. (LLL)