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.

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.

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).

The present study suggests that over the course of bipolar I disorder, cycle length and episode duration become shorter.