Comorbidity of mental disorders and substance use: a brief guide for the primary care clinician
8.1 Personality disorders
A personality disorder is an enduring pattern of inner experience, of seeing the world and relating to others in a manner that markedly deviates from cultural expectations, and includes, and results in, problematic and habitual behaviours that are pervasive and inflexible.
The onset of personality disorders occurs in adolescence or early adulthood, is stable over time, leads to impairment or distress and is not due to mental disorder or substance use.
Personality disorders are long-standing and maladaptive patterns of perceiving and responding to other people and to stressful circumstances.
Personality traits are conspicuous features of personality and are not necessarily pathological, although certain styles of personality traits may cause interpersonal problems. Personality disorders are not regarded as illnesses. However, some dominant personality traits and personality disorders can be modified and some managed on a systemic level.
8.1.1 Personality disorder subtypes
Cluster A personality disorder
Includes paranoid, schizoid and schizotypal types. Individuals display odd and eccentric behaviour.Paranoid
Person displays patterns of distrust and suspiciousness such that others’ motives are interpreted as malevolent.Schizoid
Person displays a pattern of detachment from social relationships and a restricted range of emotional expression.Schizotypal
Person displays a pattern of acute discomfort in close relationships, cognitive or perceptual distortions, and eccentricities of behaviour.Cluster B personality disorder
Includes antisocial, borderline, histrionic and narcissistic types. Individuals display dramatic, erratic and emotional behaviour.Antisocial
Person displays a pattern of disregard for, and violation of, the rights of others.Borderline
Person displays patterns of instability in interpersonal relationships, self image and effects as well as marked impulsivity.Histrionic
Person displays patterns of excessive emotionality and attention-seeking behaviour.Narcissistic
Person displays patterns of grandiosity, need for admiration and lack of empathy.Cluster C personality disorder
Includes avoidant, dependent and obsessive compulsive types. Individuals display anxious and fearful behaviours.Avoidant
Person displays patterns of social inhibition, feelings of inadequacy and hypersensitivity to negative evaluation.Dependent
Person displays patterns of submissive and clinging behaviour relating to the excessive need to be taken care of.Obsessive compulsive
Person displays patterns of preoccupation with orderliness, perfectionism and control.Personality disorders not otherwise specified
Personality disorders not otherwise specified are those where:- The individual's personality pattern meets the general criteria for a personality disorder and traits of several different personality disorders are present, but the criteria for any specific personality disorder are not met.
- The individual's personality pattern meets the general criteria for a personality disorder, but the individual is considered to have a personality disorder that is not included in the classification.
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8.1.2 Management approaches
- Limit setting and the use of therapeutic contracts are extremely important in this client group.
- It is important that clinicians remain vigilant when dealing with people who have personality disorders in order to avoid being manipulated.
- There is no specific pharmacological treatment for personality disorders. Personality disorders are not normally an indication for medication which adds to their management remaining controversial. A variety of medications have been reviewed for some types of behaviours associated with personality disorders such as impulsivity and aggression. However, good quality data relating to efficacy is limited.
- Antidepressants and mood-stabilising drugs such as carbamazepine, lithium, sodium valproate and other SSRIs are among those that have been studied. They do not provide a cure, but have assisted with some symptom control for some Cluster B personality traits****(314, 315).
- Scheduling of brief, structured and frequent visits to primary care providers is recommended. Restriction of access to emergency services and last minute appointments may be helpful in the management of personality disorders(316).
- A balance must be ensured between the fostering of dependency and providing the support and crisis intervention that is required.
- Early case management with other primary care providers (emergency department staff, locum services, after hours staff, emergency services and mental health staff) is indicated.


