title: Dimensions underlying psychotic and manic symptomatology: Extending normal-range personality traits to schizophrenia and bipolar spectra.
abstract: OBJECTIVE
  Covariance among psychiatric disorders can be accounted for by higher-order internalizing, externalizing, and psychosis dimensions, but placement of bipolar disorder within this framework has been inconsistent. Moreover, whether deviations in normal-range personality can explain psychosis and vulnerability to severe mood lability, as seen in schizophrenia and bipolar disorder, remains unclear.
  
  
  METHODS
  Exploratory factor analysis of interviewer-rated clinical symptoms in patients with schizophrenia or bipolar disorder, their first-degree biological relatives, and nonpsychiatric controls (total N=193), followed by examination of associations between symptom dimensions and self reports on personality questionnaires.
  
  
  RESULTS
  Covariance in symptoms was accounted for by five factors: positive symptoms of psychosis, negative symptoms of psychosis, disorganization, mania, and depression/anxiety. Schizophrenia and bipolar patients/relatives reported elevated negative emotionality and absorption and lower positive emotionality relative to controls. Personality did not differ between schizophrenia and bipolar patients/relatives, but there was a different pattern of associations between symptoms and personality in these groups.
  
  
  CONCLUSIONS
  Discrete dimensions reflecting psychotic, manic, and depressive symptoms emerge when a broad set of clinical symptoms is examined in a sample overrepresented by psychotic experiences and affective disturbances. Although normal-range personality traits index common phenotypes spanning schizophrenia and bipolar spectra, the same symptoms may carry different significance across disorders.
authors.affiliation: Department of Psychology, University of Minnesota, Minneapolis, Minnesota. Electronic address: syliaw@umn.edu.
authors.forename: Sylia
authors.initials: S
authors.lastname: Wilson
authors.affiliation: Veterans Affairs Health Care System, Minneapolis, Minnesota, Departments of Psychiatry and Psychology, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Sponheim
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010551:Personality / Q000502:physiology*; D011618:Psychotic Disorders / Q000503:physiopathology*; D012559:Schizophrenia / Q000503:physiopathology*