Why insomnia is more common among women

Insomnia in adults is partially explained by genetic factors, and this heritability is higher in females than in males, suggests a new study on twins.

The estimated heritability of insomnia was 59 percent for females and 38 percent for males.

"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 study first author Mackenzie Lind, a doctoral candidate at Virginia Commonwealth University in Richmond, US.

"Given the evidence for sex differences, it may be useful to specifically target females for sleep interventions," Lind noted.

Insomnia is more common in women than men and involves difficulty falling asleep or staying asleep - or regularly waking up earlier than desired - despite an adequate opportunity for sleep.

The research team analysed data from the Virginia Adult Twin Studies of Psychiatric and Substance Use Disorders, a large data set of approximately 7,500 participants.

The study was published in the journal Sleep.