PERSONALITY DISORDER: EPIDEMIOLOGY & ETIOLOGY
Presented by:
Dr. S.M. Yasir Arafat
Phase A Resident
Psychiatry, BSMMU
October 16, 2014.
Epidemiology
Epidemiology: Introduction Personality disorder is a common and chronic disorder. Its prevalence is 10-20% in the general population and
its duration is expressed in decades. Approximately one half of all psychiatric patients have
personality disorder. Predisposing factor of
substance use suicide affective disorders impulse-control disorders eating disorders anxiety disorders
Epidemiology: At different level
Community care: 2-18% (generally accepted approximate is 10%). It is more in younger adults, and may be more in males.
Primary care: 5-8% will have a primary diagnosis of PD. The rate of comorbid PD is 20-30%.
Outpatients patients 30-40% and 40-50% of inpatients have a PD. A primary diagnosis of PD occurs in about 5-15% of inpatients.
Others: 25-75% of prisoners, Antisocial PD is most prevalent.
Prevalence: At a glance
Cluster TypeNo. of Study
Mean Prevalence
General ppl- DSM
AParanoid 13 1.6 0.5-3Schizoid 13 0.8 0.5-7Schizotypal 13 0.7 0.5-5
B
Antisocial 25 1.5 2-3.5Borderline 15 1.6 1.5-2Histrionic 12 1.8 2-3Narcisstic 10 0.2 0.5-1
CAvoidant 13 1.3 0.5-5Dependent 12 0.9 0.5-5OCPD 13 2 1-2
OthersPassive-Aggressive 8 1.7
Epidemiology-Paranoid
The prevalence of paranoid PD is 0.5-2.5% of the
general population.
Referred to treatment by a spouse or an employer.
Relatives of patients with schizophrenia show a
higher incidence of paranoid PD.
The disorder is more common in men.
Higher among minority groups, immigrants, and
persons who are deaf than it is in the general
population.
Epidemiology-Schizoid
The schizoid PD may affect 7.5% of the general population.
The sex ratio is 2:1 male-to-female ratio.
Persons with the disorder tend to gravitate toward solitary jobs & many prefer night work to day work that involve little or no contact with others.
Epidemiology-Schizotypal
Schizotypal PD occurs in about 3 %.
A greater association of cases exists among the biological relatives of patients with schizophrenia.
A higher incidence among monozygotic twins than among dizygotic twins (33% versus 4%).
Epidemiology-Antisocial
The prevalence of antisocial PD is 3 % in men & 1 % in women.
It is most common in poor urban areas and among mobile residents.
Boys with the disorder come from larger families. The onset of the disorder is before the age of 15. In prison, the prevalence of antisocial PD is as
high as 75%. A familial pattern is present; the disorder is 5
times more common among first-degree relatives of men with the disorder.
Epidemiology-Borderline
Borderline PD is thought to be present in about 1-2% of the population and is twice as common in women.
An increased prevalence of MDD, alcohol use disorders, and substance abuse is found in first-degree relatives.
Epidemiology-Histrionic
Prevalence of histrionic PD of about 2 -3%.
Rates of about 10 -15% have been reported
when structured assessment is used.
The disorder is more frequent in women.
Association with somatization disorder and
alcohol use disorders.
Epidemiology-Narcissistic
Prevalence of narcissistic PD range from 2-16% in the clinical population and less than 1% in the general population.
Offspring of such parents may have a higher than usual risk for developing the disorder themselves.
The number of cases of narcissistic PD is increasing steadily.
Epidemiology-Avoidant
The prevalence of the disorder is 1-10 % of the general population.
Infants classified as having a timid temperament may be more susceptible to the disorder.
Epidemiology-Dependant
Dependent PD is more common in women.
It is more common in young children than in older ones.
Persons with chronic physical illness in childhood may be most susceptible to the disorder.
Epidemiology-OCPD
It is more common in men and is diagnosed most often in oldest children.
The disorder also occurs more frequently in first-degree biological relatives of persons with the disorder than in the general population.
Patients often have backgrounds characterized by harsh discipline.
Epidemiology-Others
NOS
Passive-Aggressive PD
Depressive PD- to occur in families in
which depressive disorders are found.
Sadomasochistic PD
Sadistic PD
Personality Change due to a GMC
Genetic Factor
Early life experience
Etiology
Etiology: Genetic factor
15,000 pairs of twins in the USA. Among monozygotic twins, the concordance for personality disorders was several times that among dizygotic twins.
Monozygotic twins reared apart are about as similar as monozygotic twins reared together. Similarities include multiple measures of personality and temperament, occupational and leisure-time interests, and social attitudes.
Etiology: Genetic-Cluster A
Cluster A PDs are more common in the biological relatives of patients with schizophrenia.
More relatives with schizotypal PD occur in the family histories of persons with schizophrenia.
Less correlation exists between paranoid or
schizoid PD and schizophrenia.
Etiology: Genetic-Cluster B
Cluster B PDs apparently have a genetic base.
Antisocial PD is associated with alcohol use disorders.
Depression is common in the family backgrounds of patients with borderline PD.
Etiology: Genetic-Cluster C
Cluster C PDs may also have a genetic base.
Obsessive-compulsive traits are more common in monozygotic twins than in dizygotic twins, and patients with OCPD show some signs associated with depression.
Etiology: Biological Factors
Hormone: Persons who exhibit impulsive traits also
often show high levels of testosterone, 17-estradiol & estrone.
Androgens increase the likelihood of aggression and sexual behavior.
DST results are abnormal in some patients with borderline personality disorder who also have depressive symptoms.
Etiology: continue
Platelet Monoamine Oxidase:
College students with low platelet MAO levels report spending more time in social activities than students with high platelet MAO levels.
Low platelet MAO levels have also been noted in some patients with schizotypal disorders
Etiology: continue
Neurotransmitters: Levels of 5-hydroxyindoleacetic acid (5-HIAA), are low in
persons who attempt suicide and in patients who are impulsive and aggressive.
Raising serotonin levels with serotonergic agents can produce dramatic changes in some character traits of personality. In many persons, serotonin reduces depression, impulsiveness, and rumination, and can produce a sense of general well-being.
Increased dopamine concentrations in the central nervous system, produced by certain psychostimulants can induce euphoria.
The effects of neurotransmitters on personality traits have generated much interest and controversy about whether personality traits are inborn or acquired.
Etiology: continue
Electrophysiology:
Changes in electrical conductance on the EEG occur in some patients with PD.
Most commonly antisocial and borderline types; these changes appear as slow-wave activity on EEGs.
Etiology: Childhood experience
Difficult infant temperament may proceed to conduct disorder in childhood and PD.
ADHD may be a risk factor for later antisocial PD.
Insecure attachment may predict later PD. Harsh and inconsistent parenting and family
pathology are related to conduct disorder, and may therefore be related to later antisocial PD.
Severe trauma in childhood may be a risk factor for borderline PD and other cluster B disorders.
Psychodynamic theories
Freudian explanations of arrested development at oral, anal, and genital stages leading to dependent, obsessional, and histrionic personalities; borderline personality organisation.
Narcissistic and borderline personalities seen as displaying primitive defence mechanisms such as splitting and projective identification.
Some see antisocial personalities as lacking aspects of superego, but more sophisticated explanation is in terms of a reaction to an overly harsh superego.
Cognitive-behavioural theories
There are maladaptive schemata. These schemata represent core beliefs which are derived from an interaction between childhood experience and pre-programmed patterns of behaviour and environmental responses.
Schemata are unconditional compared with those found in affective disorders and are formed early, often pre-verbally.
Cognitive-analytical model
Cognitive-analytical model: Borderline patients experience a range of partially dissociated self state which arise initially as a response to unmanageable external threats and are maintained by repeated threats or internal cues (memories).
Abusive experiences in childhood lead to internalisation of the harsh parental object leading to intrapsychic conflict which is repressed or produces symptomatic behaviours.
Deficits in self-reflection, poor emotional vocabulary, and narrow focus of attention lead to incoherent sense of self and others.
Dialectical behavioural model
Dialectical behavioural model: Innate temperamental vulnerability interacts with certain dysfunctional environments leading to problems with emotional regulation.
Abnormal behaviours which are manifested represent products of this emotional dysregulation or attempts to regulate intense emotional states by maladaptive problem solving.
Etiology: Defense Mechanisms Fantasy-Schizoid Dissociation or Denial- Histrionic Isolation-OCPD Projection Splitting Acting out Projective identification- Borderline PDs
References
1. Kaplan & Sadock's Synopsis of Psychiatry:
Behavioral Sciences, 10th Edition
2. Shorter Oxford Text Book of Psychiatry, 6th
Edition
3. Oxford Handbook of Psychiatry, 3rd Edition
4. Different journals