title: Differences in neuroticism and extraversion between patients with bipolar I or II and general population subjects or major depressive disorder patients.
abstract: BACKGROUND
  Whether levels of neuroticism or extraversion differ between patients with bipolar disorder (BD), major depressive disorder (MDD) and subjects from the general population, or between BD I and BD II patients, remains unclear.
  
  
  METHODS
  BD patients (n=191) from the Jorvi Bipolar Study, and MDD patients (n=358) from both the Vantaa Depression Study and the Vantaa Primary Care Depression Study cohorts, were interviewed at baseline and at 18 months. A general population comparison group (n=347) was surveyed by mail. BD patients' neuroticism and extraversion scores, measured by Eysenck Personality Inventory, were compared at an index interview, when the levels of depression and mania were lowest, with scores of MDD patients and general population controls. Comparisons were also made between BD I (n=99) and BD II (n=92) patients.
  
  
  RESULTS
  In multinomial logistic regression, BD patients had higher neuroticism (OR=1.17, p<0.001) and lower extraversion (OR=0.92, p=0.003) than the general population. When entered simultaneously into the model, the effect of extraversion disappeared. In logistic regression, the levels of neuroticism and extraversion did not differ between BD and MDD patients, or between BD I and II patients.
  
  
  CONCLUSIONS
  Patients' personality scores were not pre-morbid.
  
  
  CONCLUSIONS
  Levels of neuroticism and extraversion are unlikely to differ between BD and MDD patients, or between BD I and II patients. The overall level of neuroticism is moderately higher and extraversion somewhat lower in BD patients than in the general population. High neuroticism may be an indicator of vulnerability to both bipolar and unipolar mood disorders.
authors.affiliation: Department of Mental Health and Substance Use, National Institute of Health and Welfare, Helsinki, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Jylhä
authors.forename: Outi
authors.initials: O
authors.lastname: Mantere
authors.forename: Tarja
authors.initials: T
authors.lastname: Melartin
authors.forename: Kirsi
authors.initials: K
authors.lastname: Suominen
authors.forename: Maria
authors.initials: M
authors.lastname: Vuorilehto
authors.forename: Petri
authors.initials: P
authors.lastname: Arvilommi
authors.forename: Sami
authors.initials: S
authors.lastname: Leppämäki
authors.forename: Hanna
authors.initials: H
authors.lastname: Valtonen
authors.forename: Heikki
authors.initials: H
authors.lastname: Rytsälä
authors.forename: Erkki
authors.initials: E
authors.lastname: Isometsä
mesh_terms: D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D015331:Cohort Studies; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000523:psychology; D005120:Extraversion, Psychological; D005260:Female; D005387:Finland; D005500:Follow-Up Studies; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D009497:Neurotic Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D010555:Personality Inventory / Q000706:statistics & numerical data; D011594:Psychometrics; D012016:Reference Values; D013694:Temperament; D055815:Young Adult