A 28-year-old man is brought to the emergency department after a suicide attempt by wrist-cutting following his girlfriend's decision to take a 2-week break from their relationship. He describes feeling 'empty and abandoned' and reports a 6-year history of unstable, intense relationships that alternate between idealization and devaluation. He admits to impulsive spending sprees, binge drinking, and reckless driving. He has made three prior suicide attempts in response to perceived rejection. Mental status examination reveals appropriate affect, no psychotic features, and intact cognition. What is the most likely personality disorder diagnosis?

Explanation

## Diagnosis: Borderline Personality Disorder ### Key Clinical Features **Key Point:** Borderline personality disorder (Cluster B) is characterized by a pervasive pattern of instability in interpersonal relationships, self-image, and affect, combined with marked impulsivity and fear of abandonment. ### Diagnostic Criteria Met | DSM-5 Criterion | Patient Presentation | |-----------------|---------------------| | Frantic efforts to avoid abandonment | Suicide attempt after girlfriend's 2-week break | | Unstable, intense relationships | Alternates between idealization and devaluation | | Unstable self-image | Feels 'empty' | | Recurrent suicidal behaviour | 3 prior attempts in response to perceived rejection | | Affective instability | Emotional reactivity to relationship stress | | Chronic emptiness | Explicitly reports feeling empty | | Inappropriate, intense anger | (Implied by impulsive, self-destructive acts) | | Recurrent impulsivity | Impulsive spending, binge drinking, reckless driving | **High-Yield:** Diagnosis requires ≥5 of 9 criteria; this patient meets at least 6–7. ### Cluster B Personality Disorders: Dramatic, Emotional, Erratic **Mnemonic: ABCD** — Antisocial, Borderline, histrionic, narcissistic — Cluster B disorders share emotional dysregulation and impulsivity. | Disorder | Core Feature | Key Distinction | |----------|--------------|------------------| | **Borderline** | Fear of abandonment, unstable relationships, impulsivity, self-harm | Emotional pain drives behaviour; guilt/remorse present | | **Antisocial** | Disregard for rights of others, deceit, lack of remorse | Callous; exploits others; no emotional distress | | **Histrionic** | Excessive emotionality, attention-seeking, seductiveness | Seeks approval; shallow affect; no chronic emptiness | | **Narcissistic** | Grandiosity, need for admiration, lack of empathy | Superiority focus; not fear of abandonment | ### Clinical Pearl **Clinical Pearl:** Borderline personality disorder patients often present with suicidality or self-harm in the context of perceived rejection or abandonment. The suicide attempt here is a direct response to the girlfriend's break, a classic trigger. The pattern of 3 prior attempts reinforces the diagnosis. ### Why Not Dependent Personality Disorder? Dependent personality disorder involves submissiveness and fear of separation, but NOT the impulsivity, self-harm, intense anger, or unstable relationships seen in borderline. Dependent patients are passive and seek reassurance; borderline patients are impulsive and self-destructive. [cite:DSM-5 Diagnostic and Statistical Manual of Mental Disorders]