This review aimed to (a) examine the effects of rapid response on behavioral, cognitive, and weight-gain outcomes across the eating disorders, (b) determine whether diagnosis, treatment modality, the type of rapid response (changes in disordered eating cognitions or behaviors), or the type of behavioral outcome moderated this effect, and (c) identify factors that predict a rapid response.
Thirty-four articles met inclusion criteria from six databases. End of treatment and follow-up outcomes were divided into three categories: Behavioral (binge eating/purging), cognitive (EDE global scores), and weight gain. Average weighted effect sizes(r) were calculated.
Rapid response strongly predicted better end of treatment and follow-up cognitive and behavioral outcomes. Moderator analyses showed that the effect size for rapid response on behavioral outcomes was larger when studies included both binge eating and purging (as opposed to just binge eating) as a behavioral outcome. Diagnosis, treatment modality, and the type of rapid response experienced did not moderate the relationship between early response and outcome. The evidence for weight gain was mixed. None of the baseline variables analyzed (eating disorder psychopathology, demographics, BMI, and depression scores) predicted a rapid response.