Insomnia is not just “all in your head”, neuroscientists have found.
For the first time, seven risk genes have been identified for insomnia.
This could be the first step in understanding the biological causes of insomnia.
It helps to show that insomnia is not — as is sometimes claimed — just a psychological condition.
Professor Van Someren, one of the study’s authors, said:
“As compared to the severity, prevalence and risks of insomnia, only few studies targeted its causes.
Insomnia is all too often dismissed as being ‘all in your head’.
Our research brings a new perspective. Insomnia is also in the genes.”
The study of 113,006 people identified seven genes involved in insomnia.
There was also a genetic overlap with two other related disorders: Restless Leg Syndrome and Periodic Limb Movement Disorder.
Genetic overlap was also seen with anxiety disorders, depression and neuroticism.
Dr Anke Hammerschlag, the study’s first author, said:
“This is an interesting finding, because these characteristics tend to go hand in hand with insomnia.
We now know that this is partly due to the shared genetic basis.”
The researchers also looked at the difference between insomnia in men and women.
Professor Danielle Posthuma, another study author, said:
“Part of the genetic variants turned out to be different.
This suggests that, for some part, different biological mechanisms may lead to insomnia in men and women.
We also found a difference between men and women in terms of prevalence: in the sample we studied, including mainly people older than fifty years, 33% of the women reported to suffer from insomnia.
For men this was 24%.”
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The study was published in the journal Nature Genetics (Hammerschlag et al., 2017).