Toronto: Stress may trigger insomnia, but those with a lower amount of a particular pattern of brain waves are at even greater risk of developing the disorder, research has found.
The findings could help researchers predict who is most likely to suffer from insomnia.
"We are not all equally armed when facing stress, in terms of how we can manage our sleep. Some people are more vulnerable than others," said Thien Thanh Dang-Vu from Concordia University in Canada.
The brain -- specifically the deep, inner parts of the brain called the thalamus and cortex -- produces electromagnetic activity during sleep. When monitored by diagnostic tools, this activity appears as patterns of squiggly lines that scientists refer to as spindles.
"We found that those who had the lowest spindle activity tended to develop more disturbances in response to stress," Dang-Vu said.
For the study the researchers examined the sleep cycles of 12 Concordia students as they went through the nerve-racking experience of finals.
Measuring students' brain waves at the beginning of the school semester, the researchers found that students showing a lower spindle activity were more at risk for developing insomnia afterwards in response to the stress of the exams.
So how do you get these better spindles?
Unfortunately, there is not a lot you can do at the moment, since spindles seem to be at least partially dependent on genetics, the study said.
In the meantime, one should all keep abiding by the habits already acknowledged to promote a good night's sleep, Dang-Vu said.
"Avoid sources of stress when going to bed, preserve the bedroom environment for sleep and not for work, and avoid stimulation. Find ways to relax before going to sleep," Dang-Vu added.
The study appeared in the journal Frontiers in Human Neuroscience.