title: Risk factors of cycle acceleration in acutely admitted patients with bipolar disorder.
abstract: OBJECTIVE
  To identify risk factors associated with cycle acceleration (CA), that is, progressive decrease in duration of syndrome-free intervals between affective episodes, in acutely admitted patients with bipolar disorder (BD).
  
  
  METHODS
  All patients (n = 210) with BD I (67%) and BD II (33%) (DSM-IV) acutely admitted to a hospital serving a catchment area were compared in retrospect with regard to a positive or negative history of CA. Putative risk factors of CA with a P-value <0.05 in uni-variate tests were secondly entered into a logistic regression model.
  
  
  RESULTS
  The logistic regression model was statistically significant (P < 0.0001) and explained between 45.3% and 60.5% of the variance of CA status. 83.7% of the cases were correctly classified with a sensitivity of 87.2% and a specificity of 80.4%. Unique significant risk factors of CA were increasing severity of affective episodes (odds ratio (OR) = 28.8), BD II (OR = 3.3), hypomanic/manic episode induced by an antidepressant and/or alcohol (OR = 3.3), and female gender (OR = 3.1).
  
  
  CONCLUSIONS
  The clinical factors associated with CA may help targeting patients with BD with a course aggravation, and are in line with previously reported neuropathological processes of illness progression.
authors: Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway; Østmarka Psychiatric Department, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
authors: P I
authors: PI
authors: Finseth
authors: G
authors: G
authors: Morken
authors: U F
authors: UF
authors: Malt
authors: O A
authors: OA
authors: Andreassen
authors: A E
authors: AE
authors: Vaaler
mesh_terms: D000208:Acute Disease; D000328:Adult; D000428:Alcohol Drinking / Q000453:epidemiology / Q000523:psychology; D000928:Antidepressive Agents / Q000008:administration & dosage; D001714:Bipolar Disorder / Q000453:epidemiology* / Q000523:psychology*; D015897:Comorbidity; D018450:Disease Progression; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D009664:Norway / Q000453:epidemiology; D016017:Odds Ratio; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012737:Sex Factors; D011795:Surveys and Questionnaires
chemical_list: D000928:Antidepressive Agents
keywords: bipolar disorder; cycle acceleration; in-patient; risk factors