Contrary to popular belief, it could actually be your genetic makeup that is to blame for insomnia, not just lifestyle factors such as stress.
This is after a new study successfully identified seven genes in the human genome that put you at higher risk of developing the sleep condition.
This is the first time evidence has been found to contradict the claim that insomnia is purely a psychological condition.
Lead researcher Eus Van Someren said: āInsomnia is all too often dismissed as being all in your head. Our research brings a new perspective. Insomnia is also in the genes.ā
The international team of researchers at Vrije Universiteit Amsterdam looked at a sample of 113,006 individuals and found that the genes responsible play a role in regulation of transcription - the process where DNA is read in order to make an RNA copy of it.
One of the identified genes, MEIS1, has previously been related to two other sleep disorders; periodic limb movements of sleep (PLMS) and restless legs syndrome (RLS).
The researchers also found a strong genetic overlap with other traits, such as anxiety disorders, depression and neuroticism, and low subjective wellbeing.
Researcher Anke Hammerschlag said: āThis 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 studied whether the same genetic variants were important for men and women.
Danielle Posthuma said: āPart 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.
āWe 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%.ā
Insomnia is thought to affect 30% of people in the UK, and is particularly common in elderly people, according to the NHS.
Common symptoms are finding it difficult to fall asleep, being awake for long periods at night, waking up several times during the night, waking up early in the morning and not being able to get back to sleep.
On average, a ānormalā amount of sleep for an adult is considered to be around seven to nine hours a night. Children and babies may sleep for much longer than this, whereas older adults may sleep less.