Rapid responders to intensive treatment of bulimia nervosa.

OBJECTIVE: The purpose of the study was to examine patterns of response to treatment in bulimia nervosa and to consider the utility of differentiating rapid from slower responders.
METHOD: Participants were 166 female patients with bulimia nervosa who received specialized day hospital treatment for their eating disorder and provided complete data on symptom frequencies over the course of treatment. Symptoms and psychological functioning were assessed at the beginning and end of treatment and 2-year follow-up information was available for a subsample of 57 patients.
RESULTS: A large subgroup (41%) of patients responded rapidly to treatment (i.e., symptom frequencies of three or less during the first 4 weeks of treatment) and a smaller subgroup (31%) were considered slower responders (i.e., symptom frequencies of four or more over the first 4 weeks of treatment and three or less over the last 4 weeks of treatment). The remaining patients were either partial responders (18%) or nonresponders (10%). Rapid responders tended to be older, less symptomatic, and less preoccupied with binging before treatment (all ps < .05), but the differences were not strong. Rapid responders also had better symptom control at the end of treatment (p < .00001), were less likely to receive antidepressant/antibulimic medication during the program (p < .04), and were significantly less likely to relapse within 2 years of attending the program (p < .005). DISCUSSION: These findings demonstrate that a significant subgroup of severely ill bulimia nervosa patients had a rapid, strong, and enduring response to intensive treatment, but could not be well identified with the available measures before treatment.