An enduring pattern of inner experience and behavior that deviates markedly from cultural expectations, is inflexible, and leads to distress or impairment may meet criteria for a personality disorder. The pattern is stable over time and can be traced to adolescence or early adulthood.

Current classification includes clusters of odd/eccentric, dramatic/emotional, and anxious/fearful disorders, with specific diagnoses such as borderline, narcissistic, antisocial, and avoidant personality disorders. Traits are extreme and rigid versions of normal personality dimensions. Diagnosis requires careful assessment because overlap among categories is common and state factors such as depression can color presentation.

Treatment is often long-term and focuses on improving interpersonal functioning, emotion regulation, and self-concept. Dialectical behavior therapy, mentalization-based therapy, and specialized psychodynamic approaches have evidence for particular disorders. Change is possible yet typically gradual. Personality disorders illustrate how extreme trait configurations can organize an entire life around maladaptive strategies.

• Enduring, inflexible patterns causing impairment
• Deviate from cultural expectations
• Usually evident by early adulthood
• Respond to specialized long-term therapies