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DSM-5 personality disorder cluster A B C characteristics

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I now have comprehensive information from multiple authoritative sources (Goldman-Cecil Medicine, Harrison's, Kaplan & Sadock's Synopsis of Psychiatry) to give a full answer. Here is the complete overview:

Personality Disorder Clusters A, B, and C (DSM-5)

Personality disorders are enduring, inflexible patterns of thinking, feeling, and behavior that cause significant functional impairment or subjective distress. DSM-5 groups all 10 recognized personality disorders into three clusters based on shared phenomenological features.

Cluster A - "Odd/Eccentric"

Individuals appear strange, aloof, or eccentric. They maintain emotional distance and share features reminiscent of psychosis (without meeting full psychotic criteria). Cluster A disorders may be premorbid antecedents of psychotic illnesses.
DisorderCore Features
Paranoid PDPervasive, unjustified mistrust and suspiciousness of others' motives as malevolent; holds grudges; pathologically jealous; uses projection as a defense; ≥4 of 7 DSM-5 criteria
Schizoid PDDetachment from social relationships, restricted emotional expression, prefers solitude, no interest in sexual or close relationships, indifferent to praise or criticism; ≥4 of 7 DSM-5 criteria
Schizotypal PDDiscomfort with close relationships + cognitive/perceptual distortions + eccentric behavior; ideas of reference, magical thinking, odd speech, odd affect, suspiciousness; ≥5 of 9 DSM-5 criteria
Key distinctions:
  • Schizotypal vs. Schizoid: schizotypal has perceptual distortions and magical thinking; schizoid has flat affect and social withdrawal without oddities of thought
  • Schizotypal vs. Schizophrenia: no persistent psychosis (any psychotic episodes are brief and fragmentary)
  • ICD-10 note: schizotypal disorder is classified under psychotic disorders in ICD-10, not personality disorders
Pharmacotherapy: Antidepressants and low-dose antipsychotics have some efficacy.

Cluster B - "Dramatic/Emotional/Erratic"

Individuals are impulsive, emotionally intense, and unpredictable. Behavior is theatrical, manipulative, or violating of others' rights.
DisorderCore Features
Antisocial PDPervasive disregard for and violation of others' rights; lack of remorse; deceitfulness, impulsivity, aggressiveness; requires conduct disorder before age 15; diagnosed only age ≥18
Borderline PDInstability of interpersonal relationships, self-image, and affect + marked impulsivity; fear of abandonment; identity disturbance; self-harm; brief stress-related psychotic episodes; "splitting" (idealization/devaluation)
Histrionic PDPervasive excessive emotionality and attention-seeking; theatricality; rapidly shifting, shallow emotions; uses physical appearance to attract attention
Narcissistic PDGrandiosity (in fantasy or behavior), need for admiration, and lack of empathy; sense of entitlement; exploits others; envious
Key distinctions:
  • Antisocial vs. Borderline: both may involve criminality, but antisocial shows high novelty seeking + low harm avoidance; borderline shows high novelty seeking + high harm avoidance
  • Antisocial vs. criminal behavior: antisocial PD must involve pervasive maladaptive personality traits across multiple life domains, not just illegal behavior for gain
Pharmacotherapy: Anticonvulsant mood stabilizers (e.g., valproate, lamotrigine) and MAOIs may help with mood reactivity, behavioral dyscontrol, and rejection hypersensitivity.

Cluster C - "Anxious/Fearful"

Individuals are driven by anxiety, fear of inadequacy, or fear of separation. Behavior is inhibited, clinging, or perfectionistic.
DisorderCore Features
Avoidant PDSocial inhibition, feelings of inadequacy, hypersensitivity to negative evaluation; avoids social/occupational activities due to fear of criticism; ≥4 of 7 DSM-5 criteria
Dependent PDExcessive need to be taken care of; submissive, clinging behavior; fear of separation; difficulty making decisions without reassurance
Obsessive-Compulsive PD (OCPD)Preoccupation with orderliness, perfectionism, and mental/interpersonal control at the expense of flexibility, openness, and efficiency; NOT the same as OCD
Key distinctions:
  • Avoidant vs. Schizoid: both are socially isolated, but avoidant patients want relationships and are held back by fear; schizoid patients genuinely do not want relationships
  • OCPD vs. OCD: OCPD is an ego-syntonic personality style (the person sees nothing wrong); OCD involves ego-dystonic obsessions/compulsions causing distress
Pharmacotherapy: Medications used for anxiety disorders (SSRIs, SNRIs, buspirone) are often helpful.

Summary Table

ClusterThemeDisorders (mnemonic)
AOdd / EccentricParanoid, Schizoid, Schizotypal - "Weird"
BDramatic / Emotional / ErraticAntisocial, Borderline, Histrionic, Narcissistic - "Wild"
CAnxious / FearfulAvoidant, Dependent, Obsessive-Compulsive - "Worried"
A useful mnemonic: A = Weird, B = Wild, C = Worried

General Principles

  • Clusters overlap significantly; patients often meet criteria for more than one disorder - all applicable diagnoses should be recorded
  • Personality disorders should not be diagnosed when traits are limited to episodes of another mental disorder (e.g., major depression) or due to substance use
  • DBT (Dialectical Behavior Therapy) has the strongest evidence base, especially for borderline PD
  • Genetic contribution is well-documented; one study of 106,000 subjects identified nine loci linked to neuroticism
  • Boundaries between clusters are somewhat artificial; comorbidity with major mental disorders (mood, anxiety, psychotic) is elevated in all clusters
Sources: Goldman-Cecil Medicine, 2e, p. 3767 | Harrison's Principles of Internal Medicine, 22e, pp. 3714-3715 | Kaplan & Sadock's Synopsis of Psychiatry, pp. 1682-1690
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