title: Differentiating between Bipolar Disorder types I and II: results from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC).
abstract: OBJECTIVE
  Bipolar Disorder I (BD I) and Bipolar Disorder II (BD II) vary considerably, with differences in symptomatology, management and prognosis. For patients with depression, the distinction between BD I and BD II is not always apparent, and hinges on the differentiation between manic/mixed and hypomanic episodes. Other putative differences between patients with BD I and II exist and may assist in distinguishing between these two conditions.
  
  
  METHODS
  Data were obtained from the National Epidemiological Survey on Alcohol and Related Conditions. A total of 1429 subjects were included in our analysis based on DSM-IV criteria, 935 with BD I and 494 with BD II. We examined for differences in a number of variables including demographics, clinical features, depressive symptoms, and co-morbid conditions using t-tests and chi-square analyses for a comparison of means as well as a logistic regression for variables found to be significant.
  
  
  RESULTS
  Key differences between BD I and BD II were identified in all categories in our comparison of means. In the regression analysis, a number of variables were determined to be predictors of BD I, including unemployment (OR=0.6), taking medications for depression (OR=1.7), a history of a suicide attempt (OR=1.8), depressive symptoms such as weight gain (OR=1.7), fidgeting (OR=1.5), feelings of worthlessness (OR=1.6) and difficulties with responsibilities (OR=2.2), as well as the presence of specific phobias (OR=1.8) and Cluster C traits (OR=1.4).
  
  
  CONCLUSIONS
  Our results indicate that in addition to the differences between manic/mixed and hypomanic episodes, other significant differences exist that may be used to help differentiate BD I from BD II.
authors.affiliation: Mood and Anxiety Disorders Program, Department of Psychiatry, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada. SivanBega@yahoo.com
authors.forename: Sivan
authors.initials: S
authors.lastname: Bega
authors.forename: Ayal
authors.initials: A
authors.lastname: Schaffer
authors.forename: Benjamin
authors.initials: B
authors.lastname: Goldstein
authors.forename: Anthony
authors.initials: A
authors.lastname: Levitt
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000453:epidemiology; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D014481:United States / Q000453:epidemiology