BackgroundInformation on long-term follow up of childhood-onset anorexia nervosa is scarce. This study investigated long-term (>10 years) course, outcome and prognostic factors for hospitalized childhood-onset anorexia nervosa restricting type (ANR). MethodsForty-one ANR girls admitted to a single regional center participated. Median age at first admission was 13.3 years (range, 8.6-15.6 years). The longitudinal clinical course was retrospectively determined for a median follow-up period of 17.1 years (range, 10.4-21.1 years). We analyzed physical, psychological, and social variables to predict partial remission (PR) and full remission (FR). ResultsThe completion rate of follow up >10 years was high at 97%. At final evaluation (n = 38), distribution of prognosis was as follows: FR, n = 27 (71%); PR, n = 6 (16%); and non-remission, n = 5 (13%). The cumulative ratio of PR and FR increased during the first 5-6 years, and gradually reached a plateau at around 10 years. More than 10 years after the onset, one patient eventually achieved FR, and one patient died. Seven patients were rehospitalized and two died due to suicide during the entire follow up. On multivariate analysis, family disorders/problems rating score was a significant predictor of PR and FR. ConclusionsThis study included hospitalized ANR children aged 15 years, the youngest cohort ever reported. Long-term prognosis is generally favorable, but the mortality rate was 5%. Careful long-term follow up >10 years is needed to evaluate outcome of childhood-onset ANR, and family therapy is important in high-risk patients with family disorders/problems.