title: What happens to episode duration and cycle length over the course of bipolar disorder?
abstract: OBJECTIVE
  Published scientific literature on cycle acceleration over the course of bipolar disorder has been equivocal. The present analysis aimed to find whether episode duration and cycle lengths become shorter over the course of bipolar disorder with predominantly manic polarity.
  
  
  METHODS
  The present study comprised 150 patients diagnosed with bipolar I disorder using SCID-I for DSM-IV TR. The course of illness was charted according to the NIMH Life Chart Methodology - Clinician Retrospective Chart (NIMH - LCM CRC). Spearman correlation was used to assess the relationship of episode duration and cycle length with the number of episodes.
  
  
  RESULTS
  The mean age of the sample was 37.8 years and the average duration of illness was 13.4 years. Unipolar mania comprised 52.7% of the sample. The episode duration and the cycle length decreased with increasing number of episodes (r=-0.245, p<0.001 & r=-0.299, p<0.001 respectively).
  
  
  CONCLUSIONS
  The present study suggests that over the course of bipolar I disorder, cycle length and episode duration become shorter.
authors.affiliation: Senior Resident, Department of Psychiatry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
authors.forename: Karthick
authors.initials: K
authors.lastname: Subramanian
authors.affiliation: Associate Professor, Department of Psychiatry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
authors.forename: Shivanand
authors.initials: S
authors.lastname: Kattimani
authors.affiliation: Associate Professor, Department of Psychiatry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
authors.forename: Ravi P
authors.initials: RP
authors.lastname: Rajkumar
authors.affiliation: Assistant Professor, Department of Psychiatry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
authors.forename: Balaji
authors.initials: B
authors.lastname: Bharadwaj
authors.affiliation: Assistant Professor, Department of Psychiatry, Sree Balaji Medical College and Hospital, Chromepet, Chennai, India sidsarkar22@gmail.com.
authors.forename: Siddharth
authors.initials: S
authors.lastname: Sarkar
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000503:physiopathology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007194:India; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012044:Regression Analysis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors
keywords: bipolar disorder; longitudinal studies; recurrence; time factors