For the first time in history, seven risk genes have been linked to insomnia by an international team of scientists. This ground-breaking research pushes science forward in unraveling the mechanisms in human biology that lead to insomnia. Insomnia is frequently referred to as a psychological condition, but this new research disproves that concept. Findings were published in Nature Genetics.
One in three people have at least mild insomnia; it is one of the most common complaints in doctor’s offices. For many people, inadequate sleep continues to be a vulnerability even after treatment. Lead scientists from VU and Netherlands Institute for Neuroscience, Danielle Posthuma and Eus Van Someren, have advanced the field by starting to untangle the biological mechanisms that cause someone to be predisposed to insomnia.
These findings may offer recognition and hope to insomniacs.
A specialist in sleep and insomnia, Professor Van Someren noted that this research is the first step on a path toward a better understanding of how neurons communicate in insomniacs, leading to new developments in treatment.
Van Someren hopes that this research will lead to recognition for the condition, noting that even when considering the frequency, prevalence, severity, and risks of insomnia, few prior studies have targeted a cause. Unfortunately, insomnia is often dismissed as being a psychological disease that is ‘all in your head.’ This study, however, sheds new light on the foundation of insomnia, which lies within the genes.
Data for 113,006 individuals was collected for this research. Scientists found evidence of seven risk genes for insomnia. The identified genes play primary roles in the regulation of transcription and exocytosis. Transcription regulation is a process making any RNA copy of DNA. Exocytosis is the process in which molecules are released by cells so they can communicate with their environment. In prior studies, one of the insomnia genes, MEIS1, was associated with two sleep disorders, restless leg syndrome (RLS) and periodic limb movements of sleep (PLMS). Van Semeren and his team collaborated with Konrad Oexle and colleagues from the Institute of Neurogenomics in München, Germany. They all concluded that the variants within this gene play a role in all three conditions. Interestingly, RLS and PLMS are characterized by restless movements, while insomnia is characterized by a restless mind.
Additional findings in this research included a strong genetic overlap with other traits associated with depression, neurosis, anxiety, and subjectively feeling unwell. These characteristics are frequently associated with insomnia, and now we know that it is because there is a similar genetic basis.
Scientists wanted to know if there was a difference in the genetic variants of women versus men. Some of these variants were different, which suggests that, at least in part, women have different biological mechanisms from men that lead to insomnia. It was noted that insomnia prevalence was different for women and men as well. In this large sample, of which most participants were older than 50, 33% of women reported insomnia, but only 24% of men had the same complaint.
The seven risk genes were found in analysis of DNA and diagnoses of thousands of patients. This large cohort study from England, the UK Biobank, had the available DNA, but they did not have information about an insomnia diagnosis; however, they did ask participants if they had any difficult falling or staying asleep at night. The UK Biobank then used the Dutch Sleep Registry information to find the patients that fit the insomnia profile, marking the first time this has ever been done. Combining the knowledge gained from these two sources made all the difference in this international research.