Steinhausen HC, Villumsen MD, Hørder K, et al. - Researchers aimed at conducting a detailed study of comorbid mental disorders in anorexia nervosa during a long-term course. In this matched cohort study, they retrieved data of all patients born 1961–2008 with a first-time ICD-10 diagnosis of anorexia nervosa (AN) between 1994 and 2018 at age 8–32 from nationwide Danish register; matched controls were all the individuals without an eating disorder (ED). Follow up for a median of 9.0 years was conducted of a total of 9,985 patients with AN (93.5% females) and 49,351 matched controls. During the first 2 years and two decades after inclusion, there was about 25% and 55% risk of receiving any non-ED disorder, respectively, for patients. For the first 12 months after inclusion, they recorded a hazard ratio (HR) of seven for any non-ED; this ratio reduced to two at five or more years after inclusion. They identified large HRs during the first years ranging in 6–9 for affective, autism spectrum, personality, and obsessive–compulsive disorders with the latter showing the highest continuous increased risk. Patients aged 8–13 at diagnosis had the highest HR at 12 months after inclusion for any non-ED disorder and affective disorders.