Background: The purpose of this study was to reassess former child and adolescent psychiatric patients as adults with regard to their further development. Methods: We used a ‘catch-up’ design. A former child and adolescent psychiatric patient cohort and controls (matched for sex and age) were assessed as adults with standardized instruments (Schedules for Clinical Assessment in Neuropsychiatry, International Personality Disorder Examination, biography, psychiatric history, Global Assessment Scale, Satisfaction with Life Scale). Results: We assessed 164 former patients and 80 controls. The mean catch-up period was 13.2 years, and the subjects had a mean age of 24.8 years. Thirty-nine percent of the former patients and 25% of the controls fulfilled criteria for an ICD-10 diagnosis (present state) at catch-up, with a clear excess of personality disorders in the former patient group (13 vs. 3%). Using a survival analysis we estimated that 38% of the former patients and 10% of the controls would undergo psychiatric treatment between the ages of 18 and 31 years. Conclusions: Most former child and adolescent psychiatric patients did not come into contact with psychiatric treatment facilities again in their twenties, although they had a higher risk for a psychiatric disorder than controls. Nevertheless, the risk of later developing a personality disorder according to ICD-10 seems to be markedly raised for former child and adolescent psychiatric patients.