Almost 15 percent of Americans, or 30.8 million adults, meet diagnostic
criteria for at least one personality disorder, according to the results of
the 2001-02 National Epidemiologic Survey on Alcohol and Related Conditions
Among several types of personality disorders studied, the most common
personality disorder found among American adults in the large,
population-based study was obsessive-compulsive personality disorder (7.9
percent, or 16.4 million people), followed by paranoid personality disorder
(4.4 percent, or 9.2 million), and antisocial personality disorder (3.6
percent, or 7.6 million).
Other personality disorders affecting substantial numbers of Americans were
schizoid (6.5 million), avoidant (4.9 million), histrionic (3.8 million), and
dependent (1 million) (see chart).
Excluded from the study were borderline, schizotypal, and narcissistic
The results of the study appear in the July Journal of Clinical
"We know that these disorders often co-occur with one another and
with Axis I disorders," primary investigator Bridget Grant, Ph.D., told
Psychiatric News. "We also know they affect the course,
severity, and treatment compliance of substance use disorders—what we
didn't know was the magnitude of [personality disorders] in the
Grant said she found a great deal of comorbidity between certain
personality disorders, especially avoidant and dependent, and that these data
would be published in an upcoming issue of Comprehensive
Grant is chief of the Laboratory Epidemiology and Biometry at the National
Institute on Alcohol Abuse and Alcoholism's (NIAAA) Division of Intramural
Clinical and Biological Research.
The sample researchers used for the 2001-02 NESARC was based on the
sampling frame of the Census 2000/2001 Supplemental Survey.
Approximately 1,800 lay interviewers with the U.S. Census Bureau
administered the NESARC instrument to 43,093 adults aged 18 and older to
assess the prevalence and comorbidity of a number of mental illnesses.
As part of the survey, interviewers asked respondents a series of questions
about how they felt or acted most of the time throughout their lives"
regardless of the situation or whom they were with," according to
Interviewers used the NIAAA Alcohol Use Disorder and Associated
Disabilities Interview Schedule—DSM-IV Version (AUDADIS) as
part of the study. In order to receive a personality disorder diagnosis,
respondents had to experience the requisite number of symptoms listed in
DSM-IV for a personality disorder, and at least one of those symptoms
must have caused the person to experience social and/or occupational
Grant tested respondents for the following personality disorders: avoidant,
dependent, obsessive-compulsive, paranoid, schizoid, histrionic, and
antisocial, but excluded borderline, schizotypal, and narcissistic personality
disorders due to the large number of symptom items required to diagnose those
disorders. The researchers decided to include the latter three personality
disorders in another phase of the study.
She also examined the relationship between personality disorders and
emotional and social functioning by using the Short Form 12, Version 2
Grant found that a number of personality disorders—specifically,
avoidant, dependent, paranoid, schizoid, and antisocial personality
disorders—were associated with significant emotional disability problems
with social functioning, and occupational impairment.
However, having obsessive-compulsive personality disorder did not correlate
with higher disability scores. According to the article, "these findings
suggest that many individuals who demonstrate the preoccupation with
orderliness, perfectionism, and mental and interpersonal control
characteristic of the disorder may be high functioning even in the absence of
flexibility, openness, and efficiency."
Since Grant conducted the study among a randomly selected population-based
sample, the prevalence rates from her study diverged from those presented in
the DSM-IV-TR in some cases.
For instance, according to the DSM-IV-TR, dependent personality
disorder is "among the most frequently reported personality disorders
encountered in mental health clinics," the study report pointed out.
However, Grant's study found it to be the least common in the population.
In addition, the DSM-IV-TR estimates that the prevalence of
avoidant personality disorder in the general population is between 0.5 percent
and 1 percent, yet Grant found it to be 2.36 percent.
Grant explained that prevalence estimates of various personality disorders
in the DSM are based on relatively small, clinical studies of
patients who are receiving mental health services on an inpatient or
"You can run into problems if you rely solely on clinical
samples," she said. "If you want to know the true prevalence of a
certain disorder, you have to get out of the clinic."
Darrel Regier, M.D., M.P.H., executive director of the American Psychiatric
Institute for Research and Education and director of APA's Office of Research,
said he agreed that "prevalence rates for any disorder are best obtained
from community samples," and when such samples were available—for
prevalence rates associated with most Axis I disorders and antisocial
personality disorder—they were included in the DSM-IV-TR.
However, Regier suggested that researchers test the validity of the AUDADIS
more thoroughly by having clinicians diagnose a sample of the same community
subjects diagnosed by lay interviewers using the AUDADIS.
He also stressed the importance of conducting additional population-based
studies on prevalence rates of personality disorders before including such
data in future DSM revisions.
In her analyses, Grant identified subgroups of the population that are at
higher risk than others for having certain personality disorders. For
instance, according to the article, Native Americans are 1.6 times more likely
to have avoidant personality disorder than are whites. Blacks, Native
Americans, and Hispanics are at greater risk for paranoid personality disorder
than are whites.
In addition, being poor, divorced, or widowed are among the risk factors
for a number of personality disorders.
An abstract of the article, "Prevalence, Correlates, and
Disability of Personality Disorders in the U.S.: Results From the National
Epidemiologic Survey on Alcohol and Related Conditions," is posted