Prevalens av emosjonelt ustabil personlighetsforstyrrelse i relasjon til behandleres diagnostiseringspraksis og holdninger - en undersøkelse ved poliklinikker innen psykiatrisk divisjon ved et større helseforetak i Norge

The purpose of this study was to estimate the prevalence of borderline personality disorder (BPD) in outpatient psychiatric clinics, and investigate the relationship between prevalence of clinically diagnosed BPD and clinicians' diagnostic practice and attitudes that may influence personality disorder (PD) assessment. Prevalence-rates of BPD was assessed by the self-report questionnaire Personality Diagnostic Questionnaire 4+ (PDQ-4+), and derived from clinical BPD-diagnoses in 230 outpatients in psychiatric clinics within a large Norwegian Hospital Trust. Outpatient clinicians within the Hospital Trust (n = 33) were surveyed about their diagnostic practice and attitudes. BPD-prevalence assessed by PDQ-4+ was 34 % and significantly higher than BPD-prevalence derived from clinical diagnoses (7 %). Discrepancy in prevalence-rates of PDs and BPD between research- and clinical assessment methodology is described in the literature. The study indicated that a quarter of the clinicians use clinical assessment solely in diagnosing PDs, which is associated with underdiagnosing PDs compared to research methodology. In addition clinicians reported attitudes which may lead to reservations in diagnosing PDs. These findings can help to account for low BPD-prevalence derived from clinical diagnoses. Overall, this study indicated that BPD may be underdiagnosed within Norwegian Hospital Trusts, which has implications for treatment and prognosis