The objective of this study was to examine associations between childhood and adolescent psychiatric disorders and adult personality disorders in a group of former child psychiatric inpatients. One hundred and fifty-eight former inpatients with a mean age of 30.5 +/- 7.1 years at investigation had their childhood and adolescent Axis I disorders, obtained from their medical records, coded into DSM-IV diagnoses. Personality disorders in adulthood were assessed by means of the DSM-IV and ICD-10 Personality Questionnaire (DIP-Q). The predictive effects of child and adolescent Axis I disorders on adult personality disorders were examined with logistic regression analyses. The odds of adult schizoid, avoidant, dependent,borderline and schizotypal personality disorders increased by almost 10, five, four, three and three times, respectively, given a prior major depressive disorder. Those effects were independent of age, sex and other Axis I disorders. In addition, the odds of adult narcissistic and antisocial personality disorders increased by more than six and five times, respectively, given a prior disruptive disorder, and the odds of adult borderline, schizotypal, avoidant and paranoid personality disorders increased between two and three times given a prior sub-stance-related disorder. The results illustrate an association between mental disorders in childhood and adolescence and adult personality disorders. Identification and successful treatment of childhood psychiatric disorders may help to reduce the risk for subsequent development of an adult personality disorder.