Insomniac? Scientists may have found the genes to blame

Researchers may have pinpointed the genetic basis for insomnia, as a new study identifies seven risk genes which seem to increase the chance of suffering from the condition.

Insomnia is one of the most prevalent mental disorders, affecting roughly 1 in every 3 people in the UK, and is considered a risk factor for the onset of a number of conditions such as depression, cardiovascular disease and obesity.

Very few studies in the past, however, have set out to try and understand the cause of insomnia.

Now, for the first time, seven genes associated with the development of insomnia have been found as the result of an international study. The research, published in Nature Genetics, looked at the genomes of 113,006 participants, and compared them in a genome-wide association study to find any genetic variations which could be linked with the condition.

The most highly associated gene, MEIS1, stood out in particular because it’s already been linked with Restless Leg Syndrome and Periodic Limb Movements of Sleep, two conditions which cause restless movement.

A number of the other genes identified as risk factors for insomnia have been previously associated with conditions such as diabetes and schizophrenia.

When the researchers examined the relationship between insomnia and other traits linked to it, such as anxiety, major depressive disorder and neuroticism, they found that there was a considerable amount of genetic overlap.

“This is an interesting finding, because these characteristics tend to go hand in hand with insomnia,” said Anke Hammerschlag, a PhD student at Vrije Universiteit in Amsterdam and the lead author of the paper. “We now know that this is partly due to the shared genetic basis.”

Interestingly, the study also suggested that the genetic traits associated with insomnia may be different depending on your sex, with two different risk genes identified for men and women. This actually supports data which seems to show that insomnia doesn’t affect genders equally, with women typically showing a higher predisposition.

Professor Danielle Posthuma, one of the lead researchers of the study and also from Vrije Universiteit, believes this means there could be different mechanisms at play. “Part of the genetic variants turned out to be different,” she said. “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%.”

The fact that these seven risk genes have been pinpointed means that subsequent studies into insomnia, and the mechanisms behind it, have a solid basis to start from. At least, that’s the hope of Professor Eus Van Someren, from the Netherlands Institute for Neuroscience.

“As compared to the severity, prevalence and risks of insomnia, only few studies have targeted its causes,” he commented. “Insomnia is all too often dismissed as being ‘all in your head’. Our research brings a new perspective. Insomnia is also in the genes.”