"There's some debate as to whether you need to awaken from them because there are some patients who are actually starting to say, "I had these horrible nightmares, but I never woke up from them." But they can still recall them when they get up in the morning. So there's still some debate in the field."
Source : "Virginia Madsen on smelling Christopher Walken, getting tax advice from Arnold Schwarzenegger, and more". Interview with Will Harris, film.avclub.com. July 19, 2013.