A 32-year-old woman presents to the psychiatry clinic with her husband, who reports that she has been increasingly controlling, demanding, and emotionally volatile over the past 5 years. She becomes enraged if he spends time with friends, accuses him of infidelity without evidence, and threatens self-harm whenever he suggests couple's therapy. She describes an intense fear of abandonment and admits to impulsive spending, binge eating, and occasional cutting when stressed. She has had four jobs in the past 3 years due to conflicts with coworkers. Her relationships are marked by rapid idealization followed by devaluation. She denies any psychotic symptoms or mood episodes lasting more than a few days. What is the most likely personality disorder diagnosis?

Explanation

## Diagnosis: Borderline Personality Disorder (BPD) ### Key Diagnostic Features Present **Key Point:** Borderline Personality Disorder is characterized by a pervasive pattern of instability in interpersonal relationships, self-image, and affect, combined with marked impulsivity. | Feature | Present in This Case | |---------|----------------------| | Frantic efforts to avoid abandonment | Yes — intense fear, threats of self-harm | | Unstable intense relationships | Yes — idealization/devaluation cycle | | Unstable self-image | Yes — impulsive job changes | | Recurrent self-harm or suicidal behavior | Yes — cutting, self-harm threats | | Affective instability | Yes — rage, emotional volatility | | Chronic emptiness | Implied by impulsive behaviors | | Inappropriate intense anger | Yes — enraged over minor perceived slights | | Transient stress-related paranoia | Yes — unfounded infidelity accusations | ### Cluster B Classification **High-Yield:** BPD belongs to **Cluster B** (dramatic, emotional, erratic personality disorders), alongside Narcissistic, Histrionic, and Antisocial PD. Cluster B disorders share: - Emotional dysregulation - Impulsivity - Interpersonal instability - Attention-seeking or dramatic presentation ### Distinguishing Features from Other Cluster B Disorders **Mnemonic: ABCD for BPD core pathology** - **A**bandonment fears (core anxiety) - **B**lack-and-white thinking (splitting) - **C**hronic emptiness - **D**ysphoria and impulsivity ### Clinical Pearl **Clinical Pearl:** BPD patients often present with **rapid affective shifts within hours** (not sustained mood episodes), **intense interpersonal reactivity**, and **self-directed aggression** (cutting, burning) rather than outward violence. The combination of abandonment fear + impulsive self-harm + unstable relationships is pathognomonic. ### Diagnostic Criteria (DSM-5) Requires ≥5 of 9 criteria. This patient meets at least 7: 1. Frantic abandonment avoidance ✓ 2. Unstable relationships ✓ 3. Unstable self-image ✓ 4. Self-harm/suicidality ✓ 5. Affective instability ✓ 6. Chronic emptiness ✓ 7. Inappropriate anger ✓ 8. Transient paranoia ✓ [cite:DSM-5 Personality Disorders Section]