Background: Psychiatric problems are common in autism spectrum disorders (ASDs), but the reasons are poorly understood. We use a longitudinal population-representative cohort to examine for the first time the persistence of psychiatric problems and to identify risk factors for their occurrence and stability. Methods: Eighty-one 16-year olds (75…

Background: Existing evidence points to a substantial rise in psychosocial disorders affecting young people over the past 50 years (Rutter & Smith, 1995). However, there are major methodological challenges in providing conclusive answers about secular changes in disorder. Comparisons of rates of disorder at different time points are often…