Research unravels genetics of insomnia and links to disease

An international collaboration led by the University of Exeter Medical School and Massachusetts General Hospital (MGH) has discovered 57 areas of the genome that are linked to insomnia. The research, conducted using data from more than 450,000 people in the UK Biobank and published in Nature Genetics, also found that frequent insomnia could cause depression and coronary artery disease, a form of heart disease.

The research, funded by the National Institute of Health Research (NIHR) and the Medical Research Council (MRC), is the most comprehensive insight to date on the link between genetics and insomnia, which affects up to a third of people at any given time. It increases risk of illness and disease, which comes with a high cost to the economy.

Co-lead author Dr Samuel Jones of the University of Exeter Medical School, said: “Insomnia has a really significant impact on millions of people worldwide. We’ve long known there’s a link between insomnia and chronic disease. Now our findings suggest that depression and heart disease are actually a result of persistent insomnia.”

At the moment, cognitive behavioural therapy is thought to be the best treatment, but access is limited, meaning many people do not get effective relief.

MGH investigator Jacqueline M.Lane added: “All of these identified regions are possible new therapeutic targets for insomnia, and 16 of these regions contain known drug targets. As well, the new causal relationships indicate the potential usefulness of insomnia therapeutics as possible treatments for coronary artery disease and depression.”

Co-senior author Dr Michael Weedon of the University of Exeter Medical School, added: “There are problems with current treatments for insomnia – including issues with accessibility, addiction and side effects. We hope that understanding more about the underlying processes involved in insomnia will pave the way for better and more personalized treatments, which in turn could reduce the number of people suffering from insomnia and improve the long-term health of those that do.”

The research surveyed participants in the cohorts on their sleeping habits and whether they have difficulty falling asleep at night. This was analysed alongside responses to questions about mood to indicate whether they had depression. The researchers looked at genomic data from all participants. The findings were confirmed in nearly 15,000 people who had insomnia in the Nord-Trøndelag Health (HUNT) study, led by the Norwegian University of Science and Technology’s (NTNU), and more than 2,000 people who had been diagnosed with insomnia in the Partners Biobank cohort. In addition, the findings were validated in 85,000 people whose sleep quality, timing and duration was estimated from activity monitor data.

An investigator at the MGH Center for Genomic Medicine, senior author Richa Saxena said: “None of this work is possible without large collaborative studies across multiple institutes and countries. The UK Biobank is a transformative study in scope and scale, and we need more studies like it, particularly in groups that are underrepresented in genetic studies.”

The full paper is entitled ‘Biological and clinical insights from genetics of insomnia symptoms’.