That's a good question.---With a lot of answers! It depends on who you ask. Some doctors refer to it as a neurological disorder. Some call it a sleep disorder. Recently, it's been suggested it might be an auto-immune disorder. While others insist it's a symptom of an underlying condition.
And they're probably all right! I guess it's up to the researchers to figure out how it all fits together and come up with better treatments. Or to raise more questions probably. So little is known about sleep in general-even healthy sleep. How can they possibly restore unhealthy sleep to healthy sleep if they haven't even figured out the details of what sleep is all about yet?
If that's not complicated enough for you, let me throw this into the mix. What about human evolution? Could it be that some part of us is trying to evolve to meet the demands placed on us and another part is rejecting it, resulting in all the malfunctions of N/C? I doubt if evolution has ever been a smooth process. I KNOW! I KNOW! I sound like a crazy person. And I'm not denying it, I am a crazy person. But sometimes it takes a crazy person to find an answer that's so far out there-----where sane people fear to tread!