Researchers have identified 13 inherited traits linked to severe bipolar disorder, including issues with sleep, wake and cycle activities.
Causes of bipolar disorder (BP) are believed to be linked to both genetic and environmental factors that contribute to the problem–resulting in dramatic mood shits, according to the National Institute of Mental Health. Previous studies have suggested that disruption of the normal circadian rhythms, including both sleep and wake cycles, can precede mood shifts, as well.
“This study represents a key step in identifying the genetic roots of this disorder and, in turn, providing targets for new approaches to preventing and treating bipolar disorder,” said Dr. Nelson Freimer, who directs the Center for Neurobehavioral Genetics and holds the Maggie Gilbert Chair of Psychiatry at UCLA, in a news release.
This study involved over 500 members of 26 families from Costa Rica and Colombia who identified–of whom included members with severe bipolar disorder. From the sample, researchers discovered 13 sleep and activity measures that correlated with the behavioral disorder; some of which they were able to track to a specific chromosome.
The 13 endophenotypes (biological or behavioral markers found more commonly in those with a certain disease than without) are the following, courtesy of the release: mean of awake duration, amplitude, Hill acrophase, interdaily stability, interdaily variability, median activity, relative amplitude, mean length of sleep bouts during the sleep period, mean number of sleep bouts during awake period, time of sleep offset, time of sleep onset, mean total minutes scored awake, and WASO (total minutes in awake bouts after sleep onset).
The study is published in the Proceedings of the National Academy of Sciences (PNAS).
There are different types of bipolar disorder that range in severity. To find out more, click here.