Putative mediators of enhanced cognitive behaviour therapy for adolescents with anorexia nervosa

Abstract

The effectiveness of enhanced cognitive behaviour therapy (CBT-E) for adolescents with anorexia has been supported by several cohort studies and a non-randomized effectiveness trial comparing this treatment with family-based treatment (FBT). However, although many patients achieve a good outcome, a significant proportion still has residual psychopathology at the end of the CBT-E. These indicate the need to further work on making CBT-E for adolescents more potent. Identifying treatment mediators of CBT-E (i.e., the mechanisms through which the treatment achieves its effect) is a potential strategy that might help improve its effectiveness. Some mediators of change hypothesized for the adult version of CBT-E (i.e., the regular eating procedure and reducing body checking) should also operate in the adolescent version of the treatment. However, there are at least three additional specific procedures used in CBT-E for adolescents that might be key treatment mediators in this population: (1) the procedure of engaging the patient in the treatment and the decision to change; (2) the procedure of weight regain; and (3) the procedure of involving parents as “helpers” (not “controllers”). An opportunity, which might help to identify these potential treatment mediators, is to compare FBT and CBT-E in a randomized controlled trial. Indeed, comparing these two treatments, which seem equally effective but operate via different mechanisms, may be used to ensure that change in the putative mediator is not a consequence of the change in the outcome variable.