Group cognitive remediation therapy for younger adolescents with anorexia nervosa: a feasibility study in a Japanese sample.

Objective: Cognitive remediation therapy (CRT) aims to increase patients' cognitive flexibility by practicing new ways of thinking as well as facilitating bigger picture thinking, supporting patients with relevant tasks and encouraging an awareness of their own thinking styles. CRT has been applied in the treatment of adult anorexia nervosa (AN), and has been shown to be effective and acceptable. In adolescents, CRT has been piloted on both individual and group format. However, no studies are published in CRT for adolescents with AN in a Japanese sample. The objectives of this study were to assess the feasibility, to estimate effect sizes for the purpose of designing a larger study, and to assess the acceptability of a CRT group for younger adolescents with AN in a Japanese sample.

Methods: Group CRT interventions were carried out with a total of seven adolescents with AN. Neuropsychological and psychological assessments (motivation, self-efficacy and depression) were administered before and after the group intervention. The participants completed worksheets (documents of participants' thinking about their thinking style and the relation of the skills that they learnt through each session to real-life) and questionnaires after the group.

Results: There were small effect sizes differences between the part of the pre and post neuropsychological tests and the pre and post ability to change (motivation). There were medium effect sizes differences between the pre and post depressive symptoms and importance to change (motivation). There was a large effect size shown between the pre and post weights. All participants were able to reflect on their own thinking styles, such as having difficulty with changing feelings and the tendency to focus on details in real-life. Adolescents' feedback was positive, and the rate of dropout was low.

Conclusion: CRT groups could be feasible and acceptable for younger adolescents with AN in a Japanese sample. Trial registration UMIN No. 000020623. Registered 18 January 2016.