Four Decades of Psychological Treatment for Bulimia Nervosa and Binge-Eating Disorder: A Meta-Regression of Changes...

Earlier meta-analyses showing low rates of abstinence in treatments for bulimia nervosa (BN) and binge-eating disorder (BED) have spurred growing efforts to improve outcomes. In response, numerous trials have tested augmented, novel, or streamlined treatment protocols. However, it remains unclear whether these efforts have translated into improvements in meaningful abstinence outcomes. This meta-analysis provided updated estimates of abstinence and examined whether rates have changed over time.

Trials of psychological treatments for BN and BED that reported abstinence rates were identified from two prior reviews, with an updated search (January 2018-September 2025). Pooled abstinence rates were calculated using random-effects models. Meta-regressions tested associations between trial year and abstinence.

Ninety-nine trials (18 new) were included, 47 in BN and 52 in BED. For BN, the pooled abstinence rate was 29.4% (95% CI = 26.0, 33.1) among all randomized participants, marginally higher among completers (35.3%) and almost a third higher in all randomized augmented treatment conditions (42.9%). BN abstinence rates showed little change over time. For BED, the abstinence rate was 43.3% (95% CI = 39.2, 47.5), which was slightly higher among treatment completers and stable in various sensitivity analyses. Meta-regressions indicated BED outcomes have declined over time under certain conditions.

Many patients do not respond to front-line treatments, with no observable improvement in outcomes over four decades. Moving forward, meaningful progress will require a shift in how treatments are conceptualized and tested to achieve better outcomes, with promise emerging for strategically augmenting standard protocols and offering targted support to gradual responders.