Personality disorders

Personality disorders are a class of mental health problems in which personality traits that are fixed and maladaptive cause significant difficulties in individual psychosocial functioning. This is not the same as stating that an individual's personality is disordered, but rather their behaviours and interactional styles with others cause significant difficulties. The Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association, 2013) defines a personality disorder this way:

A Personality Disorder is an enduring pattern of inner experience and behavior that deviates markedly from the expectations of the individual's culture, is pervasive and inflexible, has an onset in adolescence or early adulthood, is stable over time, and leads to distress or impairment (American Psychiatric Association, 2013, p. 645).

The DSM-5 lists 10 personality disorders, split into three Clusters (A, B, C).

• Cluster A

◦ Paranoid (301.0) – A pattern of distrust and suspiciousness such that others’ motives are interpreted as malevolent.
◦ Schizoid (301.20) – A pattern of detachment from social relationships and a restricted range of affect.
◦ Schizotypal (301.22) – A pattern of acute discomfort in close relationships, cognitive or perceptual distortions, and eccentricities of behaviour.
• Cluster B

◦ Antisocial (301.7) – A pattern of disregard for, and violation of, the rights of others.
◦ Borderline (301.83) – A pattern of instability in interpersonal relationships, self-image, and affects, and marked impulsivity.
◦ Histrionic (301.50) – A pattern of excessive emotionality and attention seeking.
◦ Narcissistic (301.81) – A pattern of grandiosity, need for admiration, and lack of empathy.
• Cluster C

◦ Avoidant (301.82) – A pattern of social inhibition, feelings of inadequacy, and hypersensitivity to negative evaluation.
◦ Dependent (301.6) – A pattern of submissive and clinging behaviour related to an excessive need to be taken care of.
◦ Obsessive-Compulsive (301.4) – A preoccupation with orderliness, perfectionism, and control.
An individual's personality affects many aspects of day-to-day living, so the dysfunctional style can result in numerous other psychological disorders. As such, people rarely seek psychological treatment for a personality disorder. Rather, they would typically present for treatment of another problem, and the underlying personality disorder becomes apparent to the treating psychologist.