Relationships of neuroticism and extraversion with axis I and II comorbidity among patients with DSM-IV major depressive disorder

J Affect Disord. 2009 Apr;114(1-3):110-21. doi: 10.1016/j.jad.2008.06.011. Epub 2008 Aug 6.


Background: High comorbidity with axis I and II disorders among major depressive disorder (MDD) patients may in part be due to the predisposing personality dimensions of neuroticism and extraversion. However, a comprehensive view of this relationship is lacking.

Methods: MDD patients (n=193) in the Vantaa Depression Study were interviewed at baseline and at 6 and 18 months with the SCAN and SCID-II, and a general population comparison group (n=388) surveyed by mail. Neuroticism and extraversion were measured with the Eysenck Personality Inventory. A dose-exposure relationship between standardized levels of neuroticism and extraversion and type and number of comorbid axis I and II disorders among patients with MDD was hypothesized.

Results: Prevalence and number of comorbid axis I and II disorders increased significantly with increasing level of neuroticism. In contrast, as the level of extraversion increased, the prevalences of social phobia and cluster C personality disorders decreased. Patients with pure MDD or with any comorbid axis I or II disorder had z-scores of neuroticism of +0.46, +0.90 and +1.30 and of extraversion of -0.34, -0.47 and -0.84, respectively.

Limitations: Patients' personality scores were not pre-morbid.

Conclusion: Among MDD patients, a positive dose-exposure relationship appears to exist between neuroticism and prevalence and number of comorbid axis I and II disorders. A negative relationship exists between level of extraversion and prevalence of social phobia and cluster C personality disorders. These findings are consistent with the hypothesis that high neuroticism and low extraversion predispose to comorbid axis I and II disorders among patients with MDD.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Analysis of Variance
  • Anxiety Disorders / classification
  • Anxiety Disorders / diagnosis
  • Anxiety Disorders / epidemiology*
  • Anxiety Disorders / psychology
  • Comorbidity
  • Depressive Disorder, Major / diagnosis
  • Depressive Disorder, Major / epidemiology*
  • Depressive Disorder, Major / psychology
  • Diagnostic and Statistical Manual of Mental Disorders
  • Extraversion, Psychological*
  • Female
  • Finland
  • Follow-Up Studies
  • Humans
  • Interview, Psychological
  • Male
  • Middle Aged
  • Neurotic Disorders / diagnosis
  • Neurotic Disorders / epidemiology*
  • Neurotic Disorders / psychology
  • Personality Disorders / classification
  • Personality Disorders / diagnosis
  • Personality Disorders / epidemiology*
  • Personality Disorders / psychology
  • Personality Inventory
  • Phobic Disorders / epidemiology
  • Prevalence
  • Psychiatric Status Rating Scales
  • Risk Factors