Follow-Up:
I have found some helpful information on the web by using keywords: Sleep Disorders, Sleep clinics, etc. From my own independent research there seem to be some related medical diagnoses affecting sleep you may wish to research: Depression/Anxiety, ADHD/ADD, Narcolepsy (sleep paralysis/hypnogogic-hypnopompic Experiences), Night Terrors, and Fibromyalgia. My personal belief is that there are many complex hormones and neurotransmitters in the brain/body that are involved in sleep and alertness/arousal levels. Research in these areas is still fairly new but it is a popular field of research today. Many of the symptoms of Depression, ADD, Apnea, Thyroid disorders, and Fibromyalgia have overlapping symptoms. Some of the chemicals (hormones and neurotransmitters) that are involved in sleep and alertness you may want to research are: Dopamine, Seratonin, Cortisol, Norepinephrine, Adrenaline, Histamines, and Melatonin. I strongly urge anyone suffering from sleep problems to seek medical help. Many larger cities have Sleep Clinics or Medical professionals conducting research on these related disorders. I just read an article last night (sorry I don't have link) that documented actual cases of persons putting their own life in danger in a desperate quest for sleep. Sleep deprivation affects one's judgment in making decisions and has been documented in many cases of death--either from suicide or poor judgment/falling asleep at the wheel of a car,etc. Good luck & Sweet dreams!!