While the continuity between conduct disorder and antisocial personality is well documented, the association between ADHD in adolescents and borderline personality disorder in young adults was unexpected. It contrasts with the reported lack of continuity between childhood and adult borderline disorders (Lofgren and others).
The impulsive, erratic, intense temperament of ADHD children, their low self-esteem, interpersonal problems and moodiness are characteristics shared with borderline personality disorder and give face validity to this link. However, the association between ADHD and borderline personality disorder can have several explanations.
There might be a continuity between the two conditions; ADHD in children may elicit a response in their caregivers that in turn results in an increased risk for borderline personality disorder; both disorders may have some other common etiologic factor; or this association may be an artifact of poor diagnostic operationalization of the constructs.
If ADHD is confirmed as one of the pathways leading to borderline personality disorder, particularly in females, a reappraisal of the nature of this disorder might be required. In the meantime, clinicians need to keep in mind the possibility of this negative outcome when treating ADHD patients, particularly if they are female.
Females with ADHD are an under-researched group that may have severe and complex psychopathology and requires more attention. Conversely, practitioners might find it useful to inquire into the presence of ADHD symptoms during childhood when assessing patients with borderline personality disorder.
When psychosocial functioning in this group of young adults was examined (unpublished data), my colleagues and I found that having a personality disorderýand not adolescent diagnosisýwas the best predictor of poor functioning at follow-up. The adult functioning of referred adolescents who had emotional or disruptive disorders was comparable in adulthood when the effect of having a personality disorder was controlled. Developing a personality disorder seems to be the critical factor which results in poor functioning. This is consistent with findings already reported (Casey and Tyrer, Shea and others; Klein and Mannuzza; Johnson and others; Quinton and others). However, developmental variables, with the exception of quality of the family environment, did not contribute to the predictability of poor functioning over and above the effect of having a personality disorder.
Subjects with personality disorders were in trouble with the law, unemployed, cohabiting with a sexual partner, had no friends, did not go out socially, had problems in their relationships with other people and felt that their life situation was bad more often than their counterparts without a personality disorder. Antisocial personalities were typified by difficulties with the law, poor work record and early cohabitation. This is consistent with other reports (Robins and others). Other personality disorders were characterized mainly by social isolation and problems in interpersonal relationships.
These results suggest that individuals suffering from disruptive disorders in adolescence have a particularly negative personality outcome in adulthood. Not only conduct disorder but all disruptive disorders are associated with a wide range of personality psychopathology. This finding emphasizes the importance of these childhood conditions in relation to a variety of mental health problems in adulthood besides antisocial behavior. It would also appear from these results that to diminish the risk of personality disorder and poor psychosocial functioning in adult life it will be necessary to devise interventions that will improve the quality of the family environment, and will reduce disruptive behavior symptoms during childhood and disruptive disorders during adolescence.