Diagnostic assessment: BDS will be diagnosed after a diagnostic work-up by a physician based on: 1) a review of former medical discharge letters, medical records and other relevant information, 2) SCAN (Schedules for Clinical Assessment in Neuropsychiatry) which screens for general psychopathology and contains a detailed section on BDS 3) screening for ADHD, autism and conduct disorder with screening questions from the child and adolescent psychiatric interview DAWBA (Development and Well Being Assessment), 4) a physical/neurological examination and 5) standard blood tests.