Though additional studies are needed to determine potential differences between the two treatments, the authors said the findings suggest that clinicians should consider both treatments as potentially effective approaches for treating bulimia nervosa in this age group.
The study was conducted between 2007 and 2012 in cooperation with local psychotherapists at two German research centers. A total of 81 females aged 14 to 20 who met DSM-IV criteria for bulimia nervosa or partial bulimia nervosa were randomly assigned to receive regular outpatient CBT or PDT sessions for one year. Both treatments were manualized for standardization and focused specifically on treating bulimia nervosa.
Participants were assessed at baseline; at the 15th, 30th, and 45th sessions; and at the final therapy session. A follow-up assessment was also administered to participants 12 months after the end of therapy.
At the end of treatment, 33.3% CBT participants and 30.2% PDT participants were no longer diagnosed with an eating disorder. There were small differences favoring CBT for reduction in binge episodes and purging episodes, and a small difference favoring PDT in reducing subjective eating concerns among patients. The improvements remained stable at the 12-month follow-up in both groups. The researchers noted that though both treatments in the study led to similar outcomes, the small sample size did not allow detection of other potential differences between the two treatments.
“The results show that CBT and PDT are both helpful for participants with BN [bulimia nervosa],” they wrote. “PDT is especially effective when implemented in a disorder-focused manner. Clinicians treating this age group should consider CBT [or] PDT… as potentially effective approaches for older adolescents and young adults with BN.”
For related information, see the Focus article “Practice Parameter for the Assessment and Treatment of Children and Adolescents With Eating Disorders.”