Funny you mention this book, as I just pulled it out again yesterday as my 5mo old SWCAH son does not sleep unless being held- I sit up w/him in our bed at night & he sleeps in my arms.  My 2 1/2 yr old SWCAH son also was a horrible sleeper (still has some waking issues, but nothing lilke when he was a baby).  In this book by Marc Weissbluth, M.D. (we bought it at Barnes & Noble),  I have underlined sections which I brought up w/our endo because Weissbluth talks about cortisol secretion being related to the sleep wake rhythm, mood & performance, and body temp.  Our endo still didn’t seem to think that had much to do w/our sleep issues, but I don’t know -and I know every child is different so maybe it didn’t.  We ended up letting him cry it out some nights -and unfortunately that’s where we’re at w/our little one right now. Best wishes. -It really is a good book.