Study Finds High Correlation of BPD, NPD, and Schizotypal Personality Disorder

(Click here ^[1] for more coverage of Borderline Personality Disorder.)

In a previous posting BPD prevalence may be 6%, 3 times higher than previously thought ^[2], we pointed out a study that estimates 5.9% of the US population suffers from Borderline Personality Disorder ^[3]. That study was based upon the Wave 2 National Epidemiologic Survey conducted in 2004 to 2005 using interviews of approximately 35,000 Americans. The study results were published in 2008.

Now a later study published in 2008 based upon the same data set has uncovered information about the prevalence and comorbidity ^[4] of Narcissistic Personality Disorder ^[5]. The authors state that NPD is the least researched of the 10 personality disorders documented in DSM-IV-TR ^[6], so their findings are particularly useful.

The study found that:

• Lifetime prevalence of NPD is about 6%.

• Prevalence of BPD in men is about 8% versus 5% for women.

• NPD is more common among younger adults than older adults.

• NPD occurs more often among those who are separated, divorced, widowed, and never married than those who are married.

• NPD is more common among black men and women and Hispanic women and less common among Hispanic men and whites, Asians, and Native American of both genders.

• NPD is commonly present in people who also suffer from BPD. The chance of having NPD in people who have BPD is 7 times higher than those who do not.

• NPD is commonly present in people who also suffer from Schizotypal Personality Disorder ^[7]. The chance of having of NPD in people who have Schizotypal Personality Disorder is 6 times higher than for those who do not.

• NPD is commonly comorbid with substance use disorder, major depressive disorder, bipolar I disorder, anxiety disorders ^[8], specific phobias, generalized anxiety disorder, and post-traumatic stress disorder (PTSD) ^[9].

• People with NPD are less likely to have dysthymic disorder ^[10], a form of long-term depression, than those without NPD.

Further reading:

Researchers Shine Spotlight on Narcissistic Personality Disorder ^[11]

Prevalence, Correlates, Disability, and Comorbidity of DSM-IV Borderline Personality Disorder: Results From the Wave 2 National Epidemiologic Survey on Alcohol and Related Conditions (abstract) ^[12]

Introduction to the National Epidemiologic Survey on Alcohol and Related Conditions ^[13]

Introduction to the National Epidemiologic Survey on Alcohol and Related Conditions (PDF) ^[14]