Personality disorders are common, chronic conditions that affect 10-20% of the general population. They have genetic and biological factors like low serotonin levels and childhood experiences like trauma that contribute to their development. The epidemiology of specific personality disorders is discussed, such as borderline personality disorder affecting 1-2% of the population, twice as common in women. Personality disorders are also more prevalent among prison populations and relatives of those with conditions like schizophrenia.

1. PERSONALITY DISORDER: EPIDEMIOLOGY & ETIOLOGY
Presented by:
Dr. S.M. Yasir Arafat
Phase A Resident
Psychiatry, BSMMU
October 16, 2014.

2. Epidemiology

3. 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

4. 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.

5. Prevalence: At a glance
Cluster Type No. of Study Mean Prevalence
General ppl-
DSM
A
Paranoid 13 1.6 0.5-3
Schizoid 13 0.8 0.5-7
Schizotypal 13 0.7 0.5-5
B
Antisocial 25 1.5 2-3.5
Borderline 15 1.6 1.5-2
Histrionic 12 1.8 2-3
Narcisstic 10 0.2 0.5-1
C
Avoidant 13 1.3 0.5-5
Dependent 12 0.9 0.5-5
OCPD 13 2 1-2
Others
Passive-
Aggressive 8 1.7

6. 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.

7. 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.

8. 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%).

9. 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.

10. 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.

11. 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.

12. 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.

13. 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.

14. 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.

15. 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.

16. 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

17. Etiology
Genetic Factor
Early life experience

18. 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.

19. 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.

20. 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.

21. 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.

22. 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.

23. 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

24. 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.

25. 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.

26. 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.

27. 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.

28. 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.

29. 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.

30. 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.

31. Etiology: Defense Mechanisms
 Fantasy-Schizoid
 Dissociation or Denial- Histrionic
 Isolation-OCPD
 Projection
 Splitting
 Acting out
 Projective identification- Borderline PDs

32. 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