Little is known about the longer-term outcome of bulimia nervosa and the distal effects of treatment.
Prospective follow-up of subjects from two randomized controlled trials, involving a comparison of cognitive behavior therapy, behavior therapy, and focal interpersonal therapy.
Ninety percent (89/99) underwent reassessment by interview (mean [±SD] length of follow-up, 5.8±2.0 years). Almost half (46%) had a DSM-IV eating disorder; 19%, bulimia nervosa; 3%, anorexia nervosa; and 24%, eating disorder not otherwise specified. There was a low rate of other psychiatric disorders. Premorbid and paternal obesity predicted a poor outcome. While the three treatments did not differ with respect to the pro-portion of subjects with anorexia nervosa or bulimia nervosa at follow-up, they did differ once all forms of DSM-IV eating disorder were considered together. Those who had received cognitive behavior therapy or focal interpersonal therapy were doing markedly better than those who had received behavior therapy.
The longer-term outcome of bulimia nervosa depends on the nature of the treatment received. Patients who receive a treatment such as behavior therapy, which only has a short-lived effect, tend to do badly, whereas those who receive treatments such as cognitive behavior therapy or focal interpersonal therapy have a better prognosis.