A study of more than 100 civilians showed that those with chronic PTSD, either alone or with REM sleep behavior disorder (RBD), had significantly higher levels of REM sleep without atonia, reports Medscape Medical News.

“This suggests a unique biology in PTSD, which may overlap with that of RBD and could imply a future risk for neurodegenerative disease in PTSD similar to RBD patients,” coinvestigator John Feemster, medical student at the Medical College of Wisconsin, Wausau, and research assistant at the Mayo Clinic Center for Sleep Medicine, Rochester, Minnesota, told Medscape Medical News.