Sleep Disturbances as the Hallmark of PTSD Germain, A. The hypothesis that rapid eye movement (REM) sleep disturbances are the hallmark of posttraumatic stress disorder (PTSD), proposed by Ross and colleagues in 1989, has stimulated a wealth of clinical, preclinical, and animal studies on the role of sleep in the pathophysiology of PTSD. A recent review article by Dr. Anne Germain revisits this influential...