Borderline personality disorder and age of onset in major depression.

In the present report from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project, we tested the hypothesis that borderline personality disorder (BPD) accounts for the observed differences between early and late onset major depressive disorder (MDD). A total of 440 depressed outpatients were evaluated with semistructured interviews. Patients were subdivided by age of onset and the presence or absence of comorbid BPD. The overall pattern of clinical and demographic variables differed and two separate, multiple, logistic regression analyses addressed the association between age of onset and BPD in MDD patients. Comorbid BPD was not significant in the multivariable age of onset equation and the results of the multivariable analyses support the idea of difference between subtypes. It is concluded that although early age of onset is predictive of BPD, BPD is not a universal feature of early-onset MDD.