Evaluation of a German version of a brief diagnosis questionnaire of symptoms of orthorexia nervosa in patients with mental disorders (Ortho-10).

Purpose: In recent years, a new term-orthorexia nervosa (ON)-has been introduced in the field of clinical assessment and psychotherapy. Orthorexia nervosa is defined as a fixation on healthy food and a pathological obsession to eat food with more natural, higher quality ingredients. Although instruments to measure ON are available, no study on the psychometric properties of the original developed instrument by Bratman (Orthorexia nervosa: Overcoming the obsession with healthful eating, Broadway Books, New York, 2000) in a large clinical sample exists until now.