National Survey Tracks Prevalence of Personality Disorders in U.S. Population

October 18, 2007 • Science Update

NIMH-funded researchers recently reported that roughly nine percent of? U.S.adults have a personality disorder as defined by the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders, or DSM-IV. Many people with personality disorders were also found to have co-occurring major mental disorders. These findings are from the first nationally representative survey of the prevalence of personality disorders and were published in the September 2007 issue of Biological Psychiatry.

Personality disorders, which include borderline personality disorder, antisocial personality disorder, and other similar illnesses, were first defined by the DSM as diagnosable illnesses in 1980. Past research on personality disorders tended to involve study populations that were not representative of the general public and often used poorly standardized assessment tools. Therefore, previous estimates of prevalence were not widely applicable. By contrast, this study’s sample was nationally representative and employed the International Personality Disorder Examination (IPDE), a rigorous semi-structured clinical interview to diagnose personality disorders.

To determine how common personality disorders are in the United States, Mark Lenzenweger, Ph.D., of the State University of New York at Binghamton; Ronald Kessler, Ph.D., of Harvard University, and colleagues examined data from a sub-sample of National Comorbidity Survey Replication (NCS-R) respondents. This sub-sample of 5,692 adults, ages 18 and older, answered screening questions from the IPDE.

The researchers found that the prevalence for any personality disorder in the United States is 9.1 percent. Specific prevalence rates for borderline personality disorder and antisocial personality disorder were estimated at 1.4 percent and 0.6 percent, respectively. Thirty-nine percent of respondents with a personality disorder received treatment for problems related to mental health or substance use at some time during the previous 12 months. On average, respondents made two visits seeking mental health treatment. Even though the majority of cases were seen by a psychiatrist or other mental health professional, respondents were more likely to receive treatment from general medical providers than mental health specialists.

The researchers also found that people with personality disorders are very likely to have co-occurring major mental disorders, including anxiety disorders (e.g., panic disorder, post-traumatic stress disorder), mood disorders (e.g., depression, bipolar disorder), impulse control disorders (e.g., attention deficit hyperactivity disorder), and substance abuse or dependence. The association between personality disorders and major mental disorders may affect functioning and help-seeking behaviors, but the researchers caution that further research is needed to support this finding.

Lenzenweger MF, Lane MC, Loranger AW, Kessler RC. DSM-IV personality disorders in the National Comorbidity Survey Replication . Biol Psychiatry. 2007 Sep 15;62(6):553-64.