Definitions of rapid, ultrarapid, and ultradian cycling and of episode duration in pediatric and adult XXXX : a proposal to distinguish episodes from cycles.

@entity1 @entity1316 @entity162
OBJECTIVE: To propose terminology to distinguish cycles from episodes in @entity1 and adults with @entity162 ( @entity162 ). METHODS: To examine current definitions of rapid cycling and episodes in both @entity1 and adult @entity162 , an Internet search of the MEDLINE database was conducted. RESULTS: Investigations of rapid cycling in adults used the terms cycle and episode interchangeably to describe discrete periods of @entity1316 . Two studies of @entity1 and one study of adults with @entity162 , however, reported cycles occurring daily (ultradian cycling) or every few days (ultrarapid cycling). Without definitions to differentiate cycles from episodes, determining the overall duration of illness in subjects who experience ultrarapid or ultradian cycling is not possible. For example, a @entity1 cycled twice a day, every day, for 365 days (1 year). With the terminology currently in use, it is unclear whether this should be described as a single episode that had a duration of 365 days or as approximately 730 episodes (2 cycles per day x 365 days), each less than 24 hours in duration. Moreover, adults with @entity162 may have more intermittent pathology than @entity1 (e.g., adults may cycle 4 days per week, versus @entity1 may cycle 7 days per week). CONCLUSION: The following definitions are proposed. (1) Episodes will be defined by (a) the duration from onset to offset of a period of at least 2 weeks in length during which only one mood state persists or (b) the duration from onset to offset of a period of ultrarapid or ultradian cycling for at least 2 weeks. (2) Cycles will be defined by mood switches occurring daily or every few days during an episode. Further research will be needed to elucidate potential differences between @entity1 and adult cycling patterns.
