Environmental factors play a significant role in the development of sleep disorders such as insomnia, however genetics plays a bigger role than previously thought. Photo by Africa Studio/Shutterstock.com

DARIEN, Ill., Sept. 16 (UPI) -- Insomnia may partially be influenced by genetics, and the effect is stronger for women than for men, according to a recent study of twins.

Occasional symptoms of insomnia occur in 30 to 35 percent of the population. Chronic insomnia -- trouble falling or staying asleep at least 3 times a week for at least 3 months -- is persistent in 10 percent of adults.


"This study indicates that genes may play a larger role in the development of insomnia symptoms for women than for men, providing some of the first formal evidence for sex differences in an adult sample," said Mackenzie Lind, a doctoral candidate at the Virginia Institute for Psychiatric and Behavioral Genetics at Virginia Commonwealth University, in a press release. "Given the evidence for sex differences, it may be useful to specifically target females for sleep interventions."

Using data from the Virginia Adult Twin Studies of Psychiatric and Substance Use Disorders, researchers compared the insomnia symptoms of 7,500 individual participants collected from two questionnaires.

The researchers found that, as expected, environmental factors play a significant role in insomnia, but that over time genetic factors increase the chances for a person to experience the sleep disorder. The data showed that while genetics only predicted 38 percent of insomnia in men, it was significant for 59 percent of women.

The study is published in the journal Sleep.