What Are Personality Disorders

This page reflects our understanding of mental health topics as of 2026. If you are reading this at a later date, some details may no longer be current, so please verify anything important against up to date sources. If you notice anything that needs updating, we would welcome you letting us know.

Personality disorders are mental health conditions involving long-standing patterns of thinking, feeling, relating to others, and managing impulses that differ markedly from what is expected in a person's culture, are inflexible across many situations, and cause significant distress or difficulty. These patterns usually become noticeable in adolescence or early adulthood. Everyone has personality traits, and most people have some quirks or tendencies that cause occasional friction. A personality disorder is diagnosed only when patterns are pervasive, persistent, and lead to real problems in relationships, work, or wellbeing. The term can sound fixed or stigmatizing, but research shows that many people with personality disorders improve significantly over time, especially with therapy.

What Personality Disorders Look Like

Diagnostic manuals group personality disorders into three clusters:

• Cluster A, sometimes described as odd or eccentric: paranoid, schizoid, and schizotypal personality disorders, involving mistrust, detachment, or unusual thinking.
• Cluster B, dramatic, emotional, or erratic: borderline, narcissistic, histrionic, and antisocial personality disorders, involving intense emotions, unstable relationships, or disregard for others.
• Cluster C, anxious or fearful: avoidant, dependent, and obsessive-compulsive personality disorders, involving fear of rejection, reliance on others, or rigid perfectionism.

Common threads across personality disorders include:

• Recurring difficulties in close relationships.
• An unstable or rigid sense of self.
• Strong or hard-to-manage emotional reactions.
• Patterns that repeat across different settings and relationships.
• Difficulty seeing how one's own patterns contribute to problems.

Many people show traits from more than one type, and newer approaches describe personality difficulties on a spectrum of severity rather than in separate boxes.

Why They Happen

Personality disorders develop from an interaction between temperament and environment. Genetics influence traits such as emotional sensitivity, impulsivity, and anxiety. Early experiences, including trauma, neglect, inconsistent caregiving, or invalidation of feelings, shape how people learn to manage emotions and relationships. Patterns that develop as ways of coping in childhood, such as distrust or people-pleasing, can become rigid and unhelpful in adulthood. Culture and social context also influence what is considered typical and how difficulties are expressed.

Specific personality disorders have their own features, explored on the pages about emotional intensity and BPD, narcissistic personality disorder, and avoidant personality disorder.

Personality disorders often occur alongside other conditions, including depression, anxiety, substance use, and eating disorders. Sometimes these co-occurring conditions are what bring people to therapy, and personality patterns become clear over time. Treating both together tends to lead to better outcomes.

What They Are Not

• Not a character flaw or a moral judgment. They describe patterns that developed for understandable reasons.
• Not permanent. Many people improve significantly, and some no longer meet criteria over time.
• Not the same as having a strong personality. Diagnosis requires pervasive patterns that cause significant difficulty.
• Not something to diagnose in others casually. Labels used loosely can be hurtful and inaccurate.
• Not the same as OCD. Obsessive-compulsive personality disorder differs from OCD, as explained on the page about OCPD and OCD.

How They Are Assessed and Treated

Diagnosis involves a careful assessment over time, including history, patterns across relationships and settings, and sometimes structured interviews. Clinicians consider cultural context and rule out other explanations. Psychotherapy is the main treatment. Dialectical behaviour therapy, mentalization-based therapy, schema therapy, and transference-focused psychotherapy have evidence for several personality disorders. These therapies help people understand their patterns, manage emotions, and build healthier relationships. Medication may help with specific symptoms such as depression or anxiety but does not treat the personality disorder itself. A consistent, respectful therapeutic relationship is often central to change.

Getting Support at Pacific Maple Psych Centre

If long-standing patterns keep causing pain in your relationships or your sense of self, therapy can help you understand them and build new ways of relating.