What is a Personality Disorder?
A person’s personality is often considered to be the thing that makes us who we are. It is made up of our thoughts, our feelings, our behaviours and our temperament — basically the way we react to our surrounding environment. Someone with a Personality Disorder will have problems in some, or all, of these areas. These problems are intense, and long lasting, and often start becoming noticeable during adolescence or early adulthood — though it can be during childhood or later in life.
Personality Disorders can be extremely disruptive to a person’s life as it affects their thoughts, feelings, how they relate to other people, and how they deal with many situations that cross their path. It can cause problems with maintaining relationships, building friendships and the ability to deal with other people.
There are two main diagnostic manuals that are used in diagnosing Personality Disorders. ICD-10 (International Statistical Classification of Diseases and Related Health Problems Issue 10) and the DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, Version 4). For the purposes of these pages, definitions from DSM-IV will be used.
General Diagnostic Criteria for a Personality Disorder
To make a diagnosis of a Personality Disorder, these criteria must be satisfied in addition to the specific criteria listed under the individually named Personality Disorders.
A. An enduring pattern of inner experience and behaviour that deviates markedly from the expectations of the individual's culture. This pattern is manifested in two (or more) of the following areas:
- cognition (perception and interpretation of self, others and events)
- affectivity (the range, intensity, lability, and appropriateness of emotional response)
- interpersonal functioning
- impulse control
B. The enduring pattern is inflexible and pervasive across a broad range of personal and social situations.
C. The enduring pattern leads to clinically significant distress or impairment in social, occupational, or other important areas of functioning.
D. The pattern is stable and of long duration and its onset can be traced back at least to adolescence or early adulthood.
E. The enduring pattern is not better accounted for as a manifestation or consequence of another mental disorder.
F. The enduring pattern is not due to the direct physiological effects of a substance or a general medical condition such as head injury.
Persons under 18 years old who fit the criteria of a Personality Disorder are usually not diagnosed with such a disorder, although they may be diagnosed with a related disorder. Antisocial Personality Disorder cannot be diagnosed at all in persons under 18.
Individual Personality Disorders
The DSM-IV lists ten Personality Disorders, which are grouped into three clusters:
Cluster A (odd or eccentric disorders)
- Paranoid Personality Disorder
- Schizoid Personality Disorder
- Schizotypal Personality Disorder
Cluster B (dramatic, emotional, or erratic disorders)
- Antisocial Personality Disorder
- Borderline Personality Disorder
- Histrionic Personality Disorder
- Narcissistic Personality Disorder
Cluster C (anxious or fearful disorders)
- Avoidant Personality Disorder
- Dependent Personality Disorder
- Obsessive-compulsive Personality Disorder
The DSM-IV also contains a category for behavioural patterns that do not match these ten disorders, but nevertheless have the characteristics of a Personality Disorder; this category is labelled Personality Disorder NOS (Not Otherwise Specified).