Chronic insomnia may affect brain

AMSTERDAM, Netherlands, Feb. 1 (UPI) -- Dutch researchers suggest chronic insomnia may adversely affect brain microstructure -- smaller volume of gray matter.

Researchers at the Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences in Amsterdam found insomnia patients had a smaller volume of gray matter in the left orbitofrontal cortex that was strongly correlated with the severity of the patient-reported insomnia.

Ellemarije Altena and Ysbrand van der Werf and colleagues from the research group of Eus van Someren evaluated the brain volumes of people with chronic insomnia who were otherwise psychiatrically healthy and people who were healthy and without sleep problems. The researchers used voxel-based morphometry -- a neuroimaging technique that allows the recognition of brain differences.

The study findings, published in Biological Psychiatry have spurred development of the Netherlands Sleep Registry as well as further investigation into defining the subtypes of insomnia and identifying causal factors, the researchers say.

"The more severe the sleeping problems of insomniacs, the less gray 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 says in a statement.