Scientists don’t know exactly why we need to sleep–but here’s one reason to make sure you get your regular shut-eye: Sleep loss may be related to brain shrinkage.
Chronic and severely stressful situations, like those connected to depression and posttraumatic stress disorder, have been associated with smaller volumes in “stress sensitive” brain regions, such as the cingulate region of the cerebral cortex and the hippocampus, a brain region involved in memory formation, according to the authors of a new study.
llustration from Gray’s Anatomy, 1918
Published by Elsevier in the journal Biological Psychiatry, the research suggests that chronic insomnia may be another condition associated with reduced brain volume, Elsevier said in a news statement today.
Using a specialized technique called voxel-based morphometry, Ellemarije Altena and Ysbrand van der Werf from the Netherlands Institute for Neuroscience research group of Eus van Someren, evaluated the brain volumes of persons with chronic insomnia who were otherwise psychiatrically healthy, and compared them to healthy persons without sleep problems, Elsevier said.
NGS stock photo by James L. Stanfield
The researchers found that insomnia patients had a smaller volume of gray matter in the left orbitofrontal cortex, which was strongly correlated with their subjective severity of insomnia.
“We show, for the first time, that insomnia patients have lower grey matter density in brain regions involved in the evaluation of the pleasantness of stimuli, as well as in regions related to the brain’s ‘resting state’. The more severe the sleeping problems of insomniacs, the less grey matter density they have in the region involved in pleasantness evaluation, which may also be important for the recognition of optimal comfort to fall asleep,” Altena explained .
“Our group previously showed that insomniacs have difficulties with recognizing optimal comfort. These findings urge further investigation into the definition of subtypes of insomnia and their causal factors, for which we have now initiated the Netherlands Sleep Registry,” Altena added.
John Krystal, Editor of Biological Psychiatry, commented: “Insomnia is a common feature of nearly every psychiatric condition associated with reduced cortical volume; in fact, it is a common symptom of psychiatric disorders or high levels of life stress, generally.
“The study by Altena and colleagues suggests that there are additional risks of not treating insomnia, such as detrimental effects on the microstructure of the brain,” Krystal said.
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