Personality Disorders
A boards-focused tour of the 10 DSM-5 personality disorders across Clusters A/B/C — general PD criteria plus the key durations (only antisocial strictly requires age ≥18, with conduct disorder before 15; other PDs may be diagnosed under 18 if features persist ≥1 year), classic vignette buzzwords, commonly-tested look-alike distinctions, and first-line management (psychotherapy for all; DBT for borderline; no FDA-approved drug for a PD itself). Emphasizes ego-syntonic traits and high-yield next-best-step decisions.
Overview: What Defines a Personality Disorder
Personality disorders (PDs) are enduring, inflexible, pervasive patterns of inner experience and behavior that deviate markedly from cultural expectation, manifesting in ≥2 of: cognition, affect, interpersonal function, impulse control. The pattern is stable and of long duration, with onset traceable to adolescence/early adulthood. PDs are generally diagnosed in adulthood; a strict age ≥18 requirement applies only to antisocial PD — other PDs may be diagnosed before 18 if features persist ≥1 year (childhood antisocial traits are instead captured by conduct disorder). Traits are typically ego-syntonic — the patient views them as normal and rarely seeks help for them (contrast the ego-dystonic distress of OCD/anxiety). Any-PD lifetime prevalence is roughly 9–15%. PDs fall into 3 clusters: A (odd/eccentric), B (dramatic/erratic), C (anxious/fearful). Cluster A is linked to the schizophrenia spectrum; Cluster B (borderline, antisocial) is the most heavily tested. Psychotherapy is the mainstay for every PD; medications target only comorbid conditions or specific symptoms — no drug is FDA-approved to treat a personality disorder itself.
- Cluster A ('Weird') — genetically linked to schizophrenia:
- Paranoid: pervasive distrust/suspicion, reads malice into benign acts, bears grudges, questions loyalty; not psychotic. Classic defense = projection.
- Schizoid: voluntary loner, no desire for close relationships, restricted/flat affect, content alone.
- Schizotypal: eccentric appearance, magical thinking, ideas of reference, odd speech, social anxiety; schizophrenia-spectrum.
- Cluster B ('Wild'):
- Antisocial: violates others' rights, deceit, impulsivity, no remorse; requires ≥18 yo + conduct disorder before 15; M>F.
- Borderline: unstable affect/relationships/identity, abandonment fear, self-harm, splitting, chronic emptiness; F>M; Tx = DBT.
- Histrionic: theatrical, seductive/provocative, attention-seeking, shallow shifting emotions.
- Narcissistic: grandiosity, needs admiration, lacks empathy, entitled, fragile to criticism.
- Cluster C ('Worried'):
- Avoidant: desires relationships but avoids from fear of rejection/inadequacy; Tx = CBT/SSRI.
- Dependent: clingy, submissive, needs others to make decisions, fears separation.
- OCPD: perfectionism, rigidity, control, workaholism; ego-syntonic (vs ego-dystonic OCD).
- Clusters = 'Weird, Wild, Worried':
- A = Weird (odd/eccentric): Paranoid, Schizoid, Schizotypal.
- B = Wild (dramatic/emotional/erratic): Antisocial, Borderline, Histrionic, Narcissistic.
- C = Worried (anxious/fearful): Avoidant, Dependent, OCPD.
- Borderline = 'IMPULSIVE' (≥5 of 9 criteria): Impulsivity · Moodiness (affective instability) · Paranoia/dissociation under stress · Unstable self-image · Labile, intense relationships · Suicidal/self-mutilating behavior · Inappropriate intense anger · Vulnerability to abandonment · Emptiness (chronic).
- Hooks: Cluster A seem Aloof; Cluster B are Bold/Bad-actors; Cluster C are Clinging/Cowering.
Comparison: Buzzwords & First-Line Management
| Disorder | Cluster | Classic buzzword / key feature | First-line management |
|---|---|---|---|
| Paranoid | A | Distrustful, suspicious, holds grudges | Psychotherapy |
| Schizoid | A | Loner; no desire for relationships | Psychotherapy |
| Schizotypal | A | Magical thinking, ideas of reference | Psychotherapy ± low-dose antipsychotic |
| Antisocial | B | Violates rights, no remorse; ≥18 + prior conduct disorder | Psychotherapy (limited); treat comorbidities |
| Borderline | B | Splitting, abandonment fear, self-harm | DBT (1st-line) |
| Histrionic | B | Seductive, theatrical, attention-seeking | Psychotherapy |
| Narcissistic | B | Grandiose, entitled, lacks empathy | Psychotherapy |
| Avoidant | C | Wants closeness but fears rejection | CBT; SSRI |
| Dependent | C | Submissive, clingy, needs reassurance | Psychotherapy (CBT) |
| OCPD | C | Perfectionism, rigidity; ego-syntonic | CBT; SSRI |
Vignette 1: A 24-yo woman is admitted after cutting her wrists following a breakup. She first calls her nurse 'the best ever,' then rages that she's 'cruel and useless' over a delayed tray; she panics about being 'abandoned.' → Dx: Borderline PD (splitting, abandonment fear, self-harm). Next best step: ensure safety, then dialectical behavior therapy (DBT) — first-line. Team should set consistent limits and not take sides against the splitting.
Vignette 2: A 30-yo man with childhood truancy, fire-setting, and animal cruelty now shows no remorse for defrauding elderly clients. → Dx: Antisocial PD (age ≥18 plus conduct disorder before 15). Next step: firm structured limit-setting; treat comorbid substance use — psychotherapy alone is often ineffective.
Vignette 3: A 40-yo accountant misses deadlines because reports must be 'perfect,' is rigid and controlling, and sees no problem with his behavior. → Dx: OCPD (ego-syntonic; lacks the true obsessions/compulsions of OCD).
- Schizoid vs Avoidant: both isolated — schizoid doesn't want relationships; avoidant wants them but fears rejection.
- Schizotypal vs Schizophrenia: schizotypal has odd beliefs/perceptual distortions but no frank psychosis; schizophrenia = ≥6 mo of continuous signs with ≥1 mo of active psychosis.
- Paranoid PD vs Delusional disorder: PD is a lifelong suspicious trait with no fixed delusions or hallucinations.
- OCPD vs OCD: OCPD = ego-syntonic perfectionism/rigidity, no true obsessions/compulsions; OCD = ego-dystonic intrusive obsessions + compulsions, responds to SSRI + exposure/ERP.
- Antisocial vs Conduct disorder: conduct disorder is the <18 precursor; relabeled antisocial at ≥18.
- Borderline vs Bipolar: borderline shifts are rapid (minutes–hours), interpersonally triggered; bipolar episodes last days–weeks.
- Histrionic vs Narcissistic: both attention-seeking — histrionic wants to be liked/noticed; narcissistic wants to be admired/seen as superior.
Vignette 4: A 45-yo man is convinced coworkers plot to fire him and doubts his wife's fidelity without evidence, holding grudges for years — but has no hallucinations or fixed delusions. → Paranoid PD.
Vignette 5: A 28-yo woman lives alone, has no friends and no desire for any, prefers night shifts to avoid people, and shows flat affect. → Schizoid PD (contrast avoidant, who craves connection).
Vignette 6: A 22-yo man wears a 'protective' crystal, believes he senses others' thoughts, speaks in odd metaphors, and has few friends from social anxiety. → Schizotypal PD (schizophrenia-spectrum; no overt psychosis). Next step: psychotherapy; a low-dose antipsychotic may help transient perceptual/cognitive symptoms.
Vignette 7: A 35-yo woman lets her husband make every decision, feels helpless when alone, and desperately seeks a new partner immediately after a breakup. → Dependent PD.
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