Anorexia Nervosa, Atypical

Using a randomized, placebo-controlled, crossover study, this study will evaluate functional magnetic resonance imaging (fMRI) as a pharmacodynamic biomarker of opioid antagonism in adolescents with eating disorders. The hypothesis is that fMRI will be able to detect acute reward pathway modulation by naltrexone (an opioid antagonist) in pre-defined regions of interest (anterior cingulate cortex, nucleus accumbens, dorsolateral prefrontal cortex).

The purpose of this study is to examine the frequense of generalized hypermobility and pain in patients with Anorexia Nervosa. The study further explores two main questions: (1) whether generalized hypermobility may be an explanatory factor for pain in some patients with Anorexia Nervosa, and (2) whether temporomandibular joint problems (such as instability, pain, difficulties opening the mouth, locking, or clicking) contribute to eating difficulties in certain individuals with Anorexia Nervosa.

The goal of this experimental interventional study is to learn if the psychological treatment Radically Open Dialectical Behavior Therapy (RO-DBT), is feasible to conduct and provide positive effects for adolescents with eating disorders and emotional overcontrol. Participants will be those at risk for developing severe and enduring eating disorder symptoms, as they have not responded fully to previous treatment attempts. Primary outcomes are feasibility and changes in eating disorder symptoms. Secondary outcomes are changes in unhelpful behaviors and experiences related to emotional overcontrol; including psychological inflexibility, suppression of emotions, and experience of loneliness. The participants will undergo the treatment with RO-DBT, which include an approximately 22 week long treatment consisting of individual psychotherapy and parallel skills training in group.