Differences in diagnostic rules used to determine borderline personality disorder impact prevalence and associations with clinically relevant variables: Findings from the National Epidemiologic Survey on Alcohol and Related Conditions-III

Abstract

Borderline personality disorder (BPD) is a serious and understudied mental health condition associated with profound personal and public health consequences. Methodological differences in characterizing BPD may limit understanding the scope of the disorder's prevalence and effect. For example, using different diagnostic rules for BPD can affect apparent prevalence, comorbidity, and clinical presentation. This study examined how differences in diagnostic rules used to assign BPD diagnosis impacted its prevalence and associations with clinically relevant variables (e.g., demographics, comorbidity, treatment-seeking). Participants were a nationally representative sample of 36,309 noninstitutionalized U.S. adults. All variables were assessed via clinical interview (Alcohol Use Disorder and Associated Disabilities Interview Schedule-5). Six diagnostic rules determined BPD status. We used frequencies to examine prevalence rates of and associations between BPD and other clinical variables, and logistic regressions to examine the associations between each BPD variable and the other outcomes. The prevalence of BPD ranged widely-from 0.5% to 11.4%-per the diagnostic rule used. Associations between BPD diagnosis and various outcomes and clinical variables generally remained stable across all diagnostic rules, though effects became more extreme as diagnostic rules became more restrictive. Additionally, meaningful differences emerged as a function of the number of items used (30 vs. 18 items) even with no other changes to diagnostic rules. The field examining BPD and associated problem behaviors should critically consider how to most effectively characterize BPD to understand these problems more accurately and optimize the generalizability of findings. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Figure 1. Diagnostic Rules for Describing the Six BPD Variables.

Notes. BPD-A: ≥5 BPD criteria, ≥1 criterion associated with functional impairment (FI). BPD-A-18: Similar to BPD-A but composed of the 18 items that overlap between the AUDADIS-IV and −5. BPD-B: ≥5 BPD criteria, all criteria associated with FI. BPD-B-18: Similar to BPD-B but composed of the 18 items that overlap between the AUDADIS-IV and −5. BPD-C: All items for the ≥5 BPD criteria endorsed, ≥1 criterion associated with FI. BPD-D: All items for the ≥5 BPD criteria, all criteria associated with FI.

Figure 2. Prevalence Rates and Odds Ratios (OR) of Females and Males with BPD across the Six BPD Variables.

Notes. A) Prevalence rates of females and males with BPD for each of the six diagnostic rules. Solid bars=Males; Open=Females. B) ORs of females meeting criteria for BPD (compared to males) across the six BPD variables.

Figure 3. Prevalence Rates and Odds Ratios (OR) of BPD and Any Lifetime Posttraumatic Stress Disorder.

Notes. A) Prevalence rate of lifetime PTSD among people with BPD across the six diagnostic rules. B) ORs of meeting diagnostic criteria for BPD across all six diagnostic rules among people with any lifetime PTSD (compared to those without lifetime PTSD).