Wade, T.D.Georgiou, N.Keegan, E.Pellizzer, M.L.Waller, G.2025-10-082025-10-082025Behaviour Research and Therapy, 2025; 190:104754-1-104754-50005-79671873-622Xhttps://hdl.handle.net/2440/147695We examined the utility of three definitions of rapid response to treatment for predicting remission in a transdiagnostic sample receiving 10-session cognitive behaviour therapy (CBT) for an eating disorder. Both efficiency (categorising the greatest number of people as rapid responders) and predictiveness (performs best in predicting outcomes) were compared. The participants (N = 176, 93 % female, 89 % white, mean age 26.65 years) completed measures at baseline and before session 4 of CBT which was used to calculate rapid response. Remission was achieved by 64 participants (36 %) at the end of therapy. A multivariable logistic regression analysis was used to examine the contribution of rapid response, as well as baseline disordered eating, impairment, general negative emotion, to remission status. Two of the rapid response definitions were associated with participants being 2.5 times more likely to achieve remission at end of treatment. In both cases, remission was also associated with a lower level of baseline eating disorder psychopathology. The preferred definition (a reduction of ≥1.13 points on the Eating Disorder Examination Questionnaire) categorised 58 % of participants as rapid responders. These findings can be used to inform clinicians of meaningful early change that predicts positive outcomes in brief CBT for eating disorders. Early change indicators can inform collaborative consideration of barriers to progress and approaches to tackle these, making CBT more effective for more people. The conclusions should be interpreted with caution given remission was only examined at end of treatment and not over longer-term follow-up.en© 2025 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Remission; Eating disorder; Rapid response; Treatment; TransdiagnosticHumansTreatment OutcomeRemission InductionAdultMiddle AgedFemaleMaleYoung AdultFeeding and Eating DisordersCognitive Behavioral TherapyJournal article10.1016/j.brat.2025.104754738520Georgiou, N. [0000-0002-7868-8250]