Effectiveness of cognitive-behavioral outpatient treatment for bulimia nervosa

The aim of the current study was to examined the relative efficacy of two different group therapy (GT) approaches (psychoeducational –PE- vs. cognitive-behavioural –CBT-) for bulimia nervosa (BN) when compared with a control group (waiting list, WL). 100 BN patients, diagnosed according to DSM-IV criteria, who sought consecutively for treatment at the Eating Disorders Outpatient Unit, participated in the study. The whole sample were consecutively assigned to: (a) brief GT (PE, N= 50) (b) long GT (CBT, N= 50). The data were compared with a control group of 40 BN patients on the waiting list, matched for age, severity and duration of the disorder. All patients were female. For the assessment, commonly applied questionnaires in the field of eating disorders were used, such as: Eating Disorders Inventory (EDI), Bulimic Investigatory Test Edinburgh (BITE), Eating Attitudes Test (EAT-40), Social Avoidance Scale (SAD), Body Shape Questionnaire (BSQ) and Beck Depression Inventory (BDI). Outcome measures included also change in vomiting and binge-eating episodes per week, but also motivational stage. At post-treatment, 72% of the CBT group and 33% of PE group were abstinent from binge behaviours (X2=37,13; p<0.001). Good-outcome, observed in more than 75,6% of the CBT group and 38,1% of the PE group, was associated with the independent variable treatment (PE vs. CBT- p<0.001), while no treatment (WL) was followed by increase of general BMI (t-pairs= -2,38; p<0.024). The authors sought to identify as predicting factors of success: lower severity of the disorders (p<0.018) and later age of onset (p<0.05). As main conclusion, CBT (long GT) shows better outcome than PE (brief GT), whereas no treatment rarely shows spontaneous recovery. PE should be specially indicated in less severe BN patients.