Types of Personality Disorders
Personality disorders are classified into three main clusters (A, B, and C) based on shared symptom patterns, though modern classification systems like ICD-11 have moved toward dimensional severity-based approaches rather than discrete categorical diagnoses. 1, 2
Traditional Cluster-Based Classification
Cluster A: Odd or Eccentric Disorders
These disorders are characterized by odd and eccentric behaviors with common genetic and environmental risk factors 3:
- Paranoid Personality Disorder - marked by pervasive distrust and suspiciousness 2, 3
- Schizoid Personality Disorder - characterized by detachment from social relationships and restricted emotional expression 2, 3
- Schizotypal Personality Disorder - featuring cognitive or perceptual distortions and eccentric behavior 2, 3
Patients with Cluster A disorders show the highest proportion of comorbid neurodevelopmental disorders, schizophrenia, and neurocognitive disorders 4.
Cluster B: Dramatic, Emotional, or Erratic Disorders
These disorders involve emotional dysregulation and impulsive behaviors 2, 5:
- Borderline Personality Disorder - defined by onset in early adulthood, repeated suicide attempts, pervasive impulsivity strongly associated with suicidality, unstable mood and interpersonal relationships, varying self-concept oscillating between grandiosity and worthlessness, dissociative symptoms, and self-damaging behaviors 6, 1
- Antisocial Personality Disorder - characterized by disregard for others' rights and social norms 2, 5
- Histrionic Personality Disorder - marked by excessive emotionality and attention-seeking 2, 5
- Narcissistic Personality Disorder - featuring grandiosity and need for admiration 2, 5
Cluster B disorders demonstrate the largest percentage of comorbid bipolar disorders, trauma and stressor disorders, feeding and eating disorders, and substance use disorders 4.
Cluster C: Anxious or Fearful Disorders
These are the most prevalent personality disorders in the general population 2:
- Avoidant Personality Disorder - characterized by social inhibition and feelings of inadequacy 2
- Dependent Personality Disorder - marked by excessive need to be taken care of 2
- Obsessive-Compulsive Personality Disorder - featuring preoccupation with orderliness, perfectionism, and control (distinct from OCD) 2
Patients with Cluster C disorders show the greatest proportion of comorbid depressive disorders, anxiety disorders, obsessive-compulsive disorders, somatic symptom disorders, and sleep-wake disorders 4.
Modern ICD-11 Dimensional Approach
The ICD-11 has replaced the discrete categorical system with a single dimensional diagnosis of personality disorder differentiated by severity (mild, moderate, severe) rather than separate types. 1
The ICD-11 approach allows optional specification of maladaptive personality trait domains including 1:
- Negative affectivity
- Detachment
- Dissociality
- Disinhibition
- Anankastia
- Borderline pattern
This dimensional model has demonstrated superior clinical utility, with mental health professionals rating it as more useful for treatment planning, patient communication, comprehensiveness, and ease of use compared to the categorical ICD-10 system 1.
Important Clinical Considerations
Gender differences exist across all three clusters, with significant male predominance in neurodevelopmental disorder comorbidities and female predominance in sleep-wake disorder comorbidities 4.
The traditional cluster system has limitations, as many patients simultaneously meet criteria for multiple personality disorders, and the division into discrete categories lacks solid empirical foundation 1. Approximately 9% of the general U.S. population has a documented personality disorder 2.