ICD-11 dimensional personality disorder — diagnostic formulation and stepped care (MEQ)

(i) ICD-11 formulation. Personality disorder is appropriate: pervasive self and interpersonal dysfunction from late adolescence, across contexts, with distress/impairment, not better explained solely by a bipolar episode on available history. Severity: at least moderate, arguably severe if impairment is near-global with repeated high-risk crises and identity collapse — justify with multi-domain self/interpersonal failure, occupational instability, and recurrent self-harm. Trait domains: prominent negative affectivity and disinhibition; possible interpersonal antagonism features if exploitation/entitlement emerge on history. Borderline pattern: yes — instability of relationships, self-image and affects with impulsivity and self-harm fits the optional specifier. Do not stack multiple ICD-10 types as the primary structure.[1][2][3]

(ii) Differentials with discriminators. Bipolar spectrum (episode duration days–weeks; reduced sleep need with energy — not supported so far but still screen); major depression (may coexist); alcohol use disorder (coexists and amplifies risk); PTSD/complex PTSD if trauma criteria met; ADHD if childhood neurodevelopmental pattern; organic disease if atypical/late features (less likely here). Personality difficulty is too mild given multi-domain impairment and recurrent self-harm.[3]

(iii) Assessment priorities. Longitudinal history and collateral; MSE; dynamic risk (intent vs affect regulation, plan, means, alcohol, protective factors); capacity; safeguarding; cultural formulation; structured tools optional (PDS-ICD-11 severity, PiCD traits) as aids not gold standards. Medical clearance of injuries; UDS as indicated.[1][3]

(iv) Management. Severity drives intensity: specialist structured psychotherapy pathway, written crisis plan, alcohol work, consistent team (anti-splitting). Name DBT (individual + skills group + consultation team; life-threatening behaviours first) or MBT / structured clinical management if DBT unavailable. Meta-analytic evidence supports specialised psychotherapies for borderline pathology.[4][3]

(v) Pharmacotherapy. No drug treats PD as a whole (Cochrane for borderline-pattern evidence). Treat comorbidity; time-limited symptom targets with review. Example: if major depression confirmed without bipolarity, consider sertraline 50 mg orally daily with early suicide/activation review, limited dispensing given self-harm, titrate carefully — treat depression, not “personality.” Avoid chronic benzodiazepines and unreviewed polypharmacy.[5][3]