Background: Anorexia nervosa is a disorder of unknown etiology with a high rate of relapse and no known treatment. Because anorexia nervosa shares some similarities with obsessive compulsive disorder, we hypothesized that a serotonin-specific medication might be useful in the treatment of this illness.
Method: We administered an open trial of fluoxetine to 31 patients with DSM-III-R anorexia nervosa. Most anorexics were started on fluoxetine treatment after inpatient weight restoration and then discharged from the hospital and followed up as outpatients.
Results: At the time of follow-up (11 +/- 6 months on fluoxetine), 29 of the 31 patients had maintained their weight at or above 85% average body weight (97% +/- 13% average body weight for the group). We judged response as good in 10, partial in 17, and poor in 4 anorexics as measured by improvements in eating behavior, mood, and obsessional symptoms. Restrictor anorexics responded significantly better than bulimic and/or purging-type anorexics.
Conclusion: This open trial suggests that fluoxetine may help patients with anorexia nervosa maintain a healthy body weight as outpatients. The reasons for the positive effects of fluoxetine are uncertain, but the agent may help by improving eating behavior and/or reducing obsessionality, depression, and anxiety. It is important to emphasize that this was not a double-blind, placebo-controlled study. Thus we can not be certain of the efficacy of fluoxetine and caution that fluoxetine should not be used as the sole treatment of anorexia nervosa at this time.