Is insomnia in your genes?

A few sleepless nights can play havoc on our mind and body – from lethargy and fatigue to frustration and anxiety.. It can affect our concentration levels and productivity and leaves us feeling grumpy and upset. While short-term insomnia stems from changes in our normal routine such as Travel or stress, and resolves itself, long-term chronic insomnia lasts for a long time and can play havoc on our physical and mental health. Often dismissed as a condition which resides purely in our minds, insomnia is one of the most common health complaints that doctors come across. Even after treatment, poor sleep remains persistent in many people. Is insomnia in your genes?

The findings of the study suggest a strong genetic overlap with anxiety disorders, depression and neuroticism – all characteristics which correspond with insomnia.

Researchers in an international project made a breakthrough in understanding the causes of insomnia better and apparently it is not “all in our heads”. The team of researchers found seven risk genes for insomnia in a genome-wide association study (GWAS) and a genome-wide gene-based association study (GWGAS) in 113,006 individuals. These genes play an important role in transcription – a process by which the DNA is read to make a RNA copy of it, and also in exocytosis which is the release of molecules by the cells so that they can communicate with their environment.

One of the other identified genes called MEISI has been previously associated with two other sleep disorders: Periodic Limb Movements of Sleep (PLMS) and Restless Legs Syndrome (RLS). The researchers found that the genetic variants of the gene was responsible for all three sleep disorders even though PLMS and RLS is characterised by restless movements and sensations whereas insomnia is mainly about a restless stream of consciousness. The findings of this study suggest a strong genetic overlap with anxiety disorders, depression and neuroticism – all characteristics which correspond with insomnia.

In a sex-specific analysis, the researchers found that in men and women different biological mechanisms lead to insomnia and in the study sample itself, the researchers found disparity in insomnia prevalence with 33 per cent of women over 50 years suffering from insomnia while it was 24 per cent in men. The researchers also linked information from the Dutch Sleep Registry with data from the UK Biobank -a large cohort from England that has DNA available- in which they had asked their participants whether they found it difficult to fall asleep or to have an uninterrupted sleep. This helped the UK Biobank to determine which of the thousands of people met the insomnia profile and it helped the researchers understand the genetic architecture of insomnia.

While many external factors contribute to insomnia, with the findings of this study, we now know that our genes have a major role to play in insomnia. It is no longer a psychological condition but a genetic one.

Source: Nature Genetics