Chronic sleeplessness may reduce the size of a person’s brain, a recent University of Cambridge study has concluded.

The study, published in the Biological Psychiatry Journal, was led by Dr Ellemarije Altena, Research Associate at Cambridge’s Department of Clinical Neurosciences. Through the process of brain imaging, Dr Altena was able to link insomnia to density reduction in grey matter, which is fundamental to the activity of the brain.

Dr Altena, leading the study while at the Netherlands Institute for Neuroscience, recruited 21 chronic insomnia sufferers between the ages of 50 and 75, and compared their brains to those of regular sleepers.

For the insomniacs, the results showed a lower grey matter density in the regions of the brain used in decision-making.

“The finding predicts that chronic insomnia sufferers may have compromised capacities to evaluate stimuli. This could have consequences for other processes, notably decision-making,” Dr Altena explained.

She went on to say, “We can’t say what comes first: the lower grey matter density or the insomnia.” As yet, researchers have been unable to determine whether sleeplessness predates loss of grey matter or the reverse.

The study is significant because it begins to explain how insomnia disrupts the brain’s functioning. Whereas previous researchers have known that insomnia disrupts the brain’s functioning, the real cause of the malfunction had not been known.

With the help of Functional Magnetic Resonance Imaging (FMRI), scientists were able to gain a real-time insight into the effects of sleep deprivation on the brain. The technology allowed the study to be conducted under natural conditions, as opposed to laboratory conditions.

According to Dr John Krystal, Editor of Biological Psychiatry, “The study by Dr Altena and her colleagues suggests there are additional risks of not treating insomnia, such as detrimental effects on the microstructure of the brain.”

Students who regularly pull all-nighters, however, should rest assured that their brains will not be shrunk. Dr Altena told Varsity that although “not getting enough sleep is a bad idea, insomnia is a bit different from sleep deprivation.”

She added, “Insomnia is a condition where you cannot sleep whilst getting ample opportunity to sleep, which is a bit different from students not going to bed.”