U. S. researchers have found that severe sleep apnea decreases frequency of dream and nightmare recall.

Published in the Journal of Clinical Sleep Medicine, the study shows patients with severe obstructive sleep apnea report a significantly lower frequency of nightmares than patients with mild or no sleep apnea.

Dr. Jim Pagel of the University of Colorado Medical School and director of the Sleep Disorders Center of Southern Colorado in Pueblo said the study indicates obstructive sleep apnea suppresses the cognitive experience of nightmare recall.

Occurring at least weekly, frequent nightmare recall was reported by 71.4 percent of people who did not have obstructive sleep apnea and 43.2 percent of patients with mild obstructive sleep apnea, the study said.

Pagel further added that the rate of frequent nightmare recall was 29.9 percent in patients with moderate obstructive sleep apnea and 20.6 percent in patients with severe obstructive sleep apnea. (With Input from Agencies)