Borderline personality disorder among primary care depressive patients: a five-year study.

Background: Studies of depressive disorders with concurrent borderline personality disorder (BPD) in primary health care are scarce and methodologically weak. Limited epidemiological evidence suggests BPD may be common among users of primary care services. Prevalence, characteristics and outcome of primary care depressive patients with co-morbid BPD are unknown.

Methods: The Vantaa Primary Care Depression Study is a prospective five-year cohort study. A stratified random sample of 1119 patients aged 20 to 69 years was screened for depression using the Prime-MD. SCID-I/P and SCID-II interviews were used to diagnose depressive all co-morbid axis I and II disorders. Of the 137 depressive patients at baseline, 82% completed the five-year follow-up. Characteristics and outcome of patients with or without concurrent BPD were compared.

Results: BPD cases accounted for 26% at baseline and 19% at follow-up. At baseline, BPD patients had a two-fold prevalence of anxiety and previous depressive episodes; a three-fold prevalence of substance use disorders, suicidal ideation and severe economic difficulties, and a four-fold prevalence of preceding suicide attempts or unemployment compared to those without BPD. By follow-up, patients with BPD had spent more time depressed, achieved full remission slower and a higher proportion were chronically depressed.

Limitations: Diagnostic reliability of depressive disorders was excellent, but of BPD not tested. Generalizability to other primary care settings remains unknown.

Conclusions: Concurrent BPD may be relatively common among depressed primary care patients. These patients have specific, adverse characteristics and poor long-term outcome, which should be considered when developing treatments for depression in primary care.