Warnsveld

Eating disorders, including anorexia nervosa, bulimia nervosa, and their atypical forms, are challenging psychiatric illnesses with high mortality rates and often become chronic. Comorbid personality issues like negative core beliefs and early maladaptive schemas are linked to the severity and persistence of these disorders. Enhanced cognitive-behavioral therapy for eating disorders (CBT-E) is commonly used but mainly targets symptoms without addressing underlying personality factors. This study aims to evaluate the clinical and cost-effectiveness of group schema therapy (GST) for patients with eating disorders and comorbid personality pathology who do not respond well to the initial phase of CBT-E. Participants who do not show significant improvement after the first phase of CBT-E will be randomly assigned to continue CBT-E or switch to GST. GST involves outpatient care starting with five individual pre-group sessions, followed by 26 weekly group sessions and up to eight optional individual sessions. CBT-E consists of 20 to 40 weekly individual outpatient sessions. This comparison aims to assess if GST can provide better outcomes and potentially reduce long-term treatment needs compared to CBT-E. Throughout the study, participants' eating disorder symptoms will be measured using the Eating Disorder Examination Questionnaire (EDE-Q) at baseline, after four weeks (eight CBT-E sessions), at the end of treatment (up to 39 weeks post-randomization), and again at six and twelve months after treatment ends. The study also plans to examine changes in core beliefs, schemas, quality of life, and cost-effectiveness. The total treatment duration and follow-up span over several months to capture both short-term and long-term effects.