HOUSE OVERSIGHT 025107 Anxiety, Substance Abuse, many sleep disorders such as Nightmare Disorder, etc., in addition to PTSD and Depression). Research shows bi-directional causality between neuropsychiatric disorders and sleep disorders. This is a superb example of how fundamental science breakthroughs lead to clinical breakthroughs. This fact that REM is associated with emotional memories is nicely consistent with the apparent psychotic nature of dreams, because in REM Sleep the frontal cortex is 'down-regulated' (and the frontal cortex is associated with rational planning, reflection, controlling impulses), while in REM Sleep the limbic system is 'up-regulated" (and the limbic system is associated with emotions and feelings) — see Neuroimaging below. This is why dream states flood the ego with emotional fantasies without rational control. However, it is also true that the limbic system enables creative ideas, thus grounding in science the long-suspected idea that sleep and dreams can enhance creativity. As Dr. Robert Stickgold, our other advisor on the series, wrote: "It would be nice if we could talk about sleep and memory as if there were only one type of memory and one type of sleep. But this is far from the case. Sleep and memory each comes in many forms, and furthermore, memories can go through multiple forms of post-encoding processing that must be individually addressed." Immunity / Immune System. Strengthening the immune system is now a proven product of NREM sleep. Discerning the evolutionary basis for this is a key research project (i.e., it seems counter-intuitive that sleeping facilitates fitness for survival in that predators lurked in the jungles and on the plains so that going unconscious during sleep does not, at first glance, seem especially adaptive). Studies of sleep in various non-human animals reveals a direct relationship between longer periods of NREM (Slow-Wave) Sleep and a stronger immune system, especially in fighting p