Overview
The lecture introduces personality disorders as a whole: how a personality trait becomes a personality type and then a disorder, whether personality pathology is better described dimensionally or categorically, and how the biosocial model explains its origin from combined biological and environmental contributions. It then sets out the general diagnostic features of personality disorder, classifies the ten disorders into the three DSM clusters, and works through each disorder’s presentation and treatment considerations. It closes with prevalence and demographic patterns, the cultural difficulties of diagnosis, and how personality disorder is managed in general medical settings.
Learning objectives and course placement
The stated objectives are to understand personality disorders in general, to understand the biosocial model of personality, to know the prevalence, and to have an overview of personality disorders in medical care.
The lecture sits in the Mental Disorders component of the Psychological Medicine Block module in ELM 2. That block module runs in three sequential components: Medical Psychology, then Mental Disorders, then Development. A separate Psychological Medicine Vertical Module runs across both ELM 2 and ELM 3.
The course-structure slide carries no explanatory text. The relationship between the block module and the vertical module is shown only by layout, so the intended point beyond "you are here" is not stated.
Linked material:
- ELM 2 lectures: Personality and health behaviour; Health behaviour change/treatment adherence; the Mental disorder lecture series.
- ELM 2 tutorials: Mood and Anxiety; Clinical Vignettes.
Trait, type, and disorder
- Personality trait: a stable, recurring pattern of human behaviour. Examples given: a tendency to joke in serious situations, hypersensitivity to criticism, talkativeness in groups.
- Personality type: a constellation of personality traits recognisable as a frequent and familiar combination. Example given: the compulsive personality, characterised by preoccupations with work, detail, order, time, money, and cleanliness.
- Personality disorder: a constellation of personality traits that are inflexible and maladaptive, leading to difficulties in work or interpersonal relations, subjective distress, and usually both.
The three sit on the same continuum of description: the disorder is defined not by the presence of unusual traits but by their inflexibility, their maladaptiveness, and the resulting dysfunction and distress.
Dimensional or categorical?
Research has found personality disorders (and other mental health difficulties) to be associated with certain personality traits, which raises the question of whether personality disorder is best described as a category or as a position on a trait dimension. The slide illustrates this with an unlabelled continuum line and cites Samuel and Widiger (2008), a meta-analytic review of the relationships between the five-factor model and DSM-IV-TR personality disorders at facet level, and Skodol (2018), “Can personality disorders be redefined in personality trait terms?” [the slide does not state a conclusion, and the tick marks on the continuum carry no labels]
The biosocial model
The model holds that psychological disorder arises from the combined contribution of biological and environmental influences, both feeding into the same outcome.
Biological influences:
- Evolution
- Individual genes
- Brain structure and chemistry
Environmental influences:
- Invalidating environment
- Adverse childhood experiences
- Mismatched parenting style
How the two interact:
- Personality traits derive from interactions between temperament and social learning.
- Temperament sets limits on the influence of learning, for example introversion versus extraversion.
- Environmental influence affects the degree of a personality trait.
- Genetic factors account for half the variance in traits and environmental influences account for the other half, illustrated by the variance between siblings raised in the same family.
- Stressors tend to amplify already existing behavioural patterns.
- Biological vulnerability determines which type of disorder develops; psychosocial factors affect the threshold at which personality traits become maladaptive.
The division of labour in the model is the high-yield point: biology decides which disorder, psychosocial factors decide when traits tip over into maladaptive.
Defining features of personality disorder
An enduring pattern must be present in two or more of the following areas:
- Cognition: distorted thinking patterns.
- Affectivity: emotion dysregulation, covering range, intensity, lability, and appropriateness.
- Behaviour: over- or under-regulated impulse control.
- Interpersonal difficulties: attachment related.
Features of the pattern:
- Stable and long lasting
- Pervasive
- Causes dysfunction
- Deviates from social or cultural norms
- Cannot be explained by drugs, medication, or a medical condition
The three clusters
| Cluster | Descriptor | Disorders |
|---|---|---|
| A | Odd / eccentric / bizarre | Paranoid PD, Schizoid PD, Schizotypal PD |
| B | Emotional / “dramatic” / erratic | Antisocial PD, Borderline PD, Narcissistic PD, Histrionic PD |
| C | Anxious / fearful | Avoidant PD, Dependent PD, Obsessive-Compulsive PD |
Cluster A: odd, eccentric, bizarre
Paranoid personality disorder
Presentation:
- Chronically suspicious, distrusting of others
- Assumes the worst intention
- Doubts the loyalty of others
- Unforgiving, holds grudges
Treatment considerations:
- Developing trust and a solid therapeutic alliance is important
- Cognitive therapy to counter assumptions and negative beliefs about others
- No evidence that therapy is successful
- Pharmacotherapy: no treatment trials being done
Schizoid personality disorder
Presentation:
- Emotionally cold and distant
- Great difficulty forming relationships
- Social isolation, a loner
- Restricted affect, lack of emotional expressiveness
- Lack of interest in people, relationships, and most activities
Treatment considerations:
- Modelling healthy relationship skills and emotional expression
- Empathy training: teaching the person to identify, express, and respond to emotion
- Social skills training, for example role playing
- Building a support network
- Pharmacotherapy: no RCT has been done and there is no evidence of efficacy
Schizotypal personality disorder
Presentation:
- Social impairment, isolation, social discomfort or anxiety
- Odd beliefs and cognitions
- Unusual perceptions and perceptual experiences
- Odd speech and presentation
- Eccentric and peculiar behaviour
- Inappropriate or blunted affect
Treatment considerations:
- Cognitive and social skills training [the slide marks this with a question mark, indicating uncertain support]
- Pharmacotherapy: antipsychotics
Schizotypal is the one Cluster A disorder for which a specific drug class is named.
Cluster B: emotional, dramatic, erratic
Antisocial personality disorder
Presentation:
- Aggressiveness
- Superficial charm
- Self-centred
- Easily bored, high need for stimulation, sensation or thrill seeking
- Manipulative
- Lacks remorse and empathy
- Enjoys testing and provoking others
- Criminal behaviour
Treatment considerations:
- Poor evidence for treatment overall, with some evidence for moderate effects of group-based cognitive behavioural intervention
- Pharmacotherapy: studies concluded there is no consistent evidence supporting any pharmacological intervention
- Issues of treatment adherence and the risks of misuse or overdose are emphasised
- Rules and boundaries
Narcissistic personality disorder
Presentation:
- Pattern of grandiosity, overvaluing abilities and accomplishments
- May come across as boastful and pretentious
- Achievements may not be aligned with reality
- Lack of empathy for others
- Seeks admiration from others
- Self-worth that is fragile and dependent on how others perceive them
Treatment considerations:
- Some psychotherapy
- Pharmacotherapy: no evidence for pharmacological intervention
Histrionic personality disorder
Presentation:
- Flamboyant in expression and presentation
- May use physical gestures and mannerisms alongside grandiose language
- Needs high levels of attention from others
- Requires excessive approval and reassurance
- Impressionistic and superficial
- Overly concerned with appearance
Treatment considerations:
- Some psychotherapy
- Pharmacotherapy: no evidence for pharmacological intervention
Borderline personality disorder
Presentation:
- Intense mood changes with periods of numbness
- Unstable and intense interpersonal relationships
- Strong reactions to actual or perceived rejection or abandonment
- Periods of intense anger
- Poor sense of self, emptiness
- Impulsivity, for example in spending, eating, substance use, sex
- Recurrent self-harm and suicidal behaviour, gestures, or threats
Treatment considerations:
- Dialectical behaviour therapy to manage behaviours that interfere with life, delivered as both group and individual therapy
- Validation and structure
- Pharmacotherapy: poor evidence for pharmacological intervention, although it is sometimes used to assist with mood
Borderline PD is the only disorder in the lecture with a named, specific psychological treatment (DBT). Everywhere else the psychological evidence is weak or generic and the pharmacological evidence is absent.
Cluster C: anxious, fearful
Avoidant personality disorder
Presentation:
- Feeling inadequate
- Low self-esteem
- Worry about being criticised
- Avoids any situation, activity, relationship, or person where there is potential to be criticised, rejected, ridiculed, embarrassed, or disapproved of
Treatment considerations:
- Behavioural interventions: systematic desensitisation, social skills, behavioural rehearsal, assertiveness training
Dependent personality disorder
Presentation:
- Worried
- Poor self-confidence
- Submissive, clingy
- Urgency and desperation with relationship-seeking
- Relies on someone for everything in their lives
- Tendency to appear compliant
Treatment considerations:
- Psychotherapy
- The most effective interventions emphasise replacing unhealthy, maladaptive dependency with flexible, adaptive dependency
- Boundaries and limits
- Pharmacotherapy: no class of medication is consistently more effective than placebo
Obsessive-compulsive personality disorder
Presentation:
- Perfectionism
- Controlling
- Rigid rules and routines, orderly
- Loses the forest for the trees
- Rigid morals and values
- Rigid and stubborn
- Frugal with money
Treatment considerations:
- Psychotherapy
- Treat accompanying mood difficulties
Prevalence and demographic patterns
- Estimated prevalence of BPD is around 1 to 2% in the general population and 10 to 20% in clinical settings.
- Compared with other personality disorders, BPD is generally more prevalent in clinical settings.
- BPD is more commonly diagnosed in women than in men.
- ASPD is more commonly diagnosed in men than in women.
- Personality diagnoses other than ASPD in men and BPD in either gender were negligible.
- Māori diagnosed with personality disorder were over-represented both within the patient group and relative to the population.
Diagnosis across cultures
- Cultural variability: diagnosis of personality disorders in CALD (culturally and linguistically diverse) clients is influenced by cultural variations in the concept of “self”.
- Diagnostic challenges: assessment can be skewed by under- or over-estimation of cultural factors, especially when clinician and client are from different cultures.
- Migration and vulnerability: the migration process increases susceptibility to mental disorders, which complicates personality disorder diagnosis.
- Trauma complications: diagnosing personality disorders in traumatised refugees is difficult because of potential mental comorbidity and PTSD factors.
- Symptom overlap: differentiating borderline PD from complex PTSD is difficult, especially in victims of organised crime.
Personality disorders in medical settings
- Identify and treat acute symptoms, separating the medical diagnosis from the behaviours.
- Identify and treat problems of pain, anxiety, and depression.
- Identify and resolve problems that cover the medical diagnosis or treatment.
- Tailor the management plan and patient education to the patient’s personality style.
Self-test
- Distinguish a personality trait, a personality type, and a personality disorder.
- List the four areas in which an enduring pattern must appear for a personality disorder to be diagnosed, with what goes wrong in each.
- List the five features that characterise the pattern in personality disorder.
- List the biological and environmental influences in the biosocial model.
- Explain what the biosocial model says about how much of trait variance is genetic versus environmental, and give the example used.
- Explain the respective roles of biological vulnerability and psychosocial factors in determining the disorder that develops.
- Explain why stressors matter in the biosocial model.
- Name the three clusters with their descriptive labels and the disorders in each.
- Describe the presentation of paranoid personality disorder and state the main treatment consideration.
- Distinguish schizoid from schizotypal personality disorder.
- List the treatment considerations for schizoid personality disorder.
- Describe the presentation of antisocial personality disorder.
- Explain what the evidence says about treating antisocial personality disorder, psychologically and pharmacologically.
- Distinguish narcissistic from histrionic personality disorder.
- Describe the presentation of borderline personality disorder.
- Describe the treatment approach for borderline personality disorder.
- Distinguish avoidant from dependent personality disorder.
- Explain what the most effective interventions for dependent personality disorder aim to replace, and with what.
- Describe the presentation of obsessive-compulsive personality disorder.
- State the prevalence of BPD in the general population and in clinical settings, and the gender pattern for BPD and ASPD.
- Explain what the lecture reports about Māori and personality disorder diagnosis.
- Explain why diagnosing personality disorder is difficult in culturally and linguistically diverse clients.
- Explain why complex PTSD complicates the diagnosis of borderline personality disorder.
- List the four principles for managing a patient with personality disorder in a medical setting.
- A patient with a long history of chronic suspicion attends a medical clinic, doubts the motives of the team, and holds grudges over past appointments. Using the lecture’s material, describe how you would approach management.
- A young woman presents to the emergency department after self-harm, describes intense anger and emptiness, and reports repeated relationship breakdowns triggered by feared abandonment. Name the likely personality disorder and the specific therapy indicated.
- Integrative: using the biosocial model and the treatment evidence across the ten disorders, explain why treatment of personality disorder is generally psychological rather than pharmacological.
Answers
Reveal answers
- A trait is a stable, recurring pattern of behaviour (for example hypersensitivity to criticism). A type is a constellation of traits recognisable as a frequent and familiar combination (for example the compulsive personality: work, detail, order, time, money, cleanliness). A disorder is a constellation of traits that are inflexible and maladaptive, causing difficulties in work or interpersonal relations, subjective distress, and usually both.
- Cognition (distorted thinking patterns), affectivity (emotion dysregulation in range, intensity, lability, appropriateness), behaviour (over- or under-regulated impulse control), and interpersonal difficulties (attachment related). Two or more areas must be affected.
- Stable and long lasting, pervasive, causes dysfunction, deviates from social or cultural norms, and cannot be explained by drugs, medication, or a medical condition.
- Biological: evolution, individual genes, brain structure and chemistry. Environmental: invalidating environment, adverse childhood experiences, mismatched parenting style. Both feed into the production of psychological disorder.
- Genetic factors account for half the variance in traits and environmental influences account for the other half. The example is the variance between siblings raised in the same family.
- Biological vulnerability determines which type of disorder develops; psychosocial factors affect the threshold at which personality traits become maladaptive.
- Stressors tend to amplify already existing behavioural patterns rather than create new ones.
- Cluster A, odd/eccentric/bizarre: paranoid, schizoid, schizotypal. Cluster B, emotional/“dramatic”/erratic: antisocial, borderline, narcissistic, histrionic. Cluster C, anxious/fearful: avoidant, dependent, obsessive-compulsive.
- Chronically suspicious and distrusting, assumes the worst intention, doubts others’ loyalty, unforgiving and holds grudges. The main consideration is developing trust and a solid therapeutic alliance; cognitive therapy can be used to counter negative assumptions about others, but there is no evidence therapy is successful and no pharmacotherapy trials have been done.
- Schizoid is emotionally cold and distant with restricted affect, great difficulty forming relationships, social isolation, and lack of interest in people and activities. Schizotypal adds odd beliefs and cognitions, unusual perceptions, odd speech and presentation, and eccentric behaviour, alongside social impairment and social anxiety; inappropriate or blunted affect. Antipsychotics are named for schizotypal only.
- Modelling healthy relationship skills and emotional expression, empathy training (identifying, expressing, and responding to emotion), social skills training such as role play, and building a support network. No RCT has been done for pharmacotherapy and there is no evidence of efficacy.
- Aggressiveness, superficial charm, self-centredness, easily bored with a high need for stimulation and thrill seeking, manipulative, lacking remorse and empathy, enjoys testing and provoking others, and criminal behaviour.
- Evidence for treatment is poor overall, with some evidence for moderate effects from group-based cognitive behavioural intervention. Studies concluded there is no consistent evidence supporting any pharmacological intervention, and treatment adherence, misuse, and overdose risk are emphasised. Rules and boundaries are important.
- Narcissistic centres on grandiosity: overvalued abilities and accomplishments that may not align with reality, boastful and pretentious presentation, lack of empathy, seeking admiration, and fragile self-worth dependent on others’ perceptions. Histrionic centres on attention: flamboyant expression, physical gestures and grandiose language, need for high levels of attention, excessive approval and reassurance, impressionistic and superficial style, and preoccupation with appearance.
- Intense mood changes with periods of numbness, unstable and intense relationships, strong reactions to actual or perceived rejection or abandonment, periods of intense anger, poor sense of self and emptiness, impulsivity (spending, eating, substance use, sex), and recurrent self-harm and suicidal behaviour, gestures, or threats.
- Dialectical behaviour therapy, in group and individual format, to manage behaviours that interfere with life, plus validation and structure. Pharmacotherapy has poor evidence but is sometimes used to assist with mood.
- Avoidant is driven by feelings of inadequacy, low self-esteem, and worry about criticism, leading to avoidance of any situation, activity, relationship, or person carrying potential for criticism, rejection, ridicule, embarrassment, or disapproval; treated with behavioural interventions (systematic desensitisation, social skills, behavioural rehearsal, assertiveness training). Dependent is driven by poor self-confidence and reliance on others: worried, submissive and clingy, urgent and desperate in relationship-seeking, relying on someone for everything, and appearing compliant; treated with psychotherapy, boundaries and limits.
- Replacing unhealthy, maladaptive dependency with flexible, adaptive dependency.
- Perfectionism, controlling, rigid rules and routines and orderliness, losing the forest for the trees, rigid morals and values, rigidity and stubbornness, and frugality with money. Treated with psychotherapy and by treating accompanying mood difficulties.
- BPD is around 1 to 2% in the general population and 10 to 20% in clinical settings, and is more prevalent in clinical settings than other personality disorders. BPD is more commonly diagnosed in women, ASPD more commonly in men. Diagnoses other than ASPD in men and BPD in either gender were negligible.
- Māori diagnosed with personality disorder were over-represented both within the patient group and relative to the population.
- Diagnosis in CALD clients is influenced by cultural variations in the concept of “self”, and assessment can be skewed by under- or over-estimation of cultural factors, particularly when clinician and client come from different cultures. Migration itself increases susceptibility to mental disorder, further complicating the picture.
- Differentiating borderline PD from complex PTSD is difficult, and diagnosis in traumatised refugees is complicated by mental comorbidity and PTSD factors, especially in victims of organised crime.
- Identify and treat acute symptoms while separating the medical diagnosis from the behaviours; identify and treat pain, anxiety, and depression; identify and resolve problems covering the medical diagnosis or treatment; and tailor the management plan and patient education to the patient’s personality style.
- The picture fits paranoid personality disorder. Prioritise building trust and a solid therapeutic alliance, use cognitive therapy to counter the assumptions and negative beliefs about others while recognising there is no evidence therapy is successful, and note that no pharmacotherapy trials exist. In the medical setting, separate the medical diagnosis from the behaviours, treat any pain, anxiety or depression, resolve the problems obscuring the medical issue, and tailor the plan and education to this personality style.
- Borderline personality disorder; dialectical behaviour therapy, in group and individual form, with validation and structure.
- The biosocial model attributes personality traits to interactions between temperament and social learning, with genes and environment contributing half the variance each, and with psychosocial factors setting the threshold at which traits become maladaptive; the modifiable element is therefore largely learning and environment. This matches the treatment evidence in the lecture: pharmacotherapy has no evidence in paranoid, schizoid, antisocial, narcissistic, histrionic, or dependent PD, and only poor evidence in borderline (used to assist mood), with antipsychotics named only in schizotypal. Psychological approaches (DBT, cognitive therapy, social skills and empathy training, behavioural interventions) target the learned, environmentally shaped component and so carry what evidence there is.