Borderline Personality Disorder
Definition
DSM-5 requires five of nine criteria: frantic efforts to avoid abandonment, unstable intense relationships, identity disturbance, impulsivity, recurrent self-harm or suicidal behaviour, affective instability, chronic emptiness, inappropriate intense anger, and transient stress-related paranoia or dissociation.
Five of nine produces 256 possible combinations, and two people with the diagnosis may share only one criterion.
ICD-11 abandoned the categorical personality disorders entirely in favour of a severity plus trait-domain model, retaining a borderline pattern qualifier only after considerable argument.
History
The term is a historical accident. It originally described patients thought to be on the border between neurosis and psychosis, a distinction nobody now uses, and the name has outlived the theory that produced it.
It entered DSM-III in 1980. Many clinicians and most service-user groups prefer emotionally unstable personality disorder or complex post-traumatic presentations, and some reject a personality-disorder framing altogether.
Theory
Linehan's biosocial theory is the most influential: a transaction between biologically-based emotional vulnerability — high sensitivity, high reactivity, slow return to baseline — and an invalidating environment, each shaping the other over development.
Mentalisation-based accounts (Fonagy, Bateman) propose that the core deficit is in mentalising: understanding one's own and others' behaviour in terms of mental states, which fails under attachment-system arousal.
Both reframe behaviour usually read as manipulation as a learned solution to unbearable affect, which is the clinically important move.
Research
Prevalence around 1 to 2 percent in the community and far higher in clinical settings. Diagnosed more often in women, though whether that reflects prevalence or diagnostic bias is genuinely contested, with evidence for bias.
Prognosis is much better than the label implies. Longitudinal studies find high rates of symptomatic remission over 10 to 16 years, with most people no longer meeting criteria. Functional recovery lags behind symptomatic remission substantially.
DBT, mentalisation-based treatment, transference-focused psychotherapy and schema therapy all have trial evidence. No medication has good evidence as a primary treatment.
Applications
Structured psychological treatment is first line. Medication is used widely and supported poorly, and polypharmacy in this group is common and hard to justify.
Risk assessment needs care: chronic risk is not acute risk, and treating every self-harm episode as an emergency has iatrogenic consequences of its own.
Criticism
- The diagnosis is used pejoratively. There is documented evidence that clinicians respond less helpfully to patients with this label, and service users report this consistently.
- The trauma overlap is substantial. A large proportion of people diagnosed report childhood adversity, and whether this is better described as complex PTSD is a live argument, not a settled one.
- Gender bias in diagnosis has been demonstrated experimentally with identical vignettes.
- The category is heterogeneous to the point of weakness, which is part of why ICD-11 moved away from it.
- The name is wrong and everyone knows it is wrong.
References
- Linehan, M. M. (1993). Cognitive-Behavioral Treatment of Borderline Personality Disorder. Guilford Press.
- Zanarini, M. C., et al. (2012). Attainment and stability of sustained symptomatic remission and recovery. American Journal of Psychiatry, 169(5), 476-483.
- Bateman, A., & Fonagy, P. (2004). Psychotherapy for Borderline Personality Disorder. Oxford University Press.
- Sheehan, L., Nieweglowski, K., & Corrigan, P. (2016). The stigma of personality disorders. Current Psychiatry Reports, 18(1), 11.