Objective: The authors examined the comorbidity of borderline personality disorder with other personality disorders in a series of consecutively admitted adolescents. For comparison, the comorbidity of borderline personality disorder with other personality disorders was also examined in a series of adults consecutively admitted to the same hospital during the same period.
Method: A total of 138 adolescents and 117 adults were reliably assessed with the Personality Disorder Examination, a semistructured diagnostic interview for DSM-III-R personality disorders. Sixty-eight adolescents and 50 adults met the diagnostic criteria for borderline personality disorder. The co-occurrence of other personality disorders in the group of subjects with borderline personality disorder was statistically compared to that in the group without borderline personality disorder, for adolescents and adults separately.
Results: For the adults, Bonferroni-corrected chi-square analysis revealed significant diagnostic co-occurrence with borderline personality disorder for antisocial personality disorder only. For the adolescents, borderline personality disorder showed significant co-occurrence with schizotypal and passive-aggressive personality disorders.
Conclusions: In the adults, borderline personality disorder was significantly comorbid only with another cluster B disorder. The adolescents, by comparison, displayed a broader pattern of comorbidity of borderline personality disorder, encompassing aspects of clusters A and C. These results suggest that the borderline personality disorder diagnosis may represent a more diffuse range of psychopathology in adolescents than in adults.