Why won't my 19 month old sleep??? We went through the from 13-15months old and it was miserable. My son who was sleeping through the night stopped. Sometimes he would scream when I put him to bed. Sometimes he would wake in the middle of the night and scream and be up for 2 hours around 1am. I figured it was a long if things... he cut 4 molars at that time, and his sister was born. I despise cry it out, but it had been months of this happening 4-5 times a week, and my ped suggested it. 3 nights of the torturous CIO (20-30 min), and it wasn't a problem again. Recently, it happened again. He's 19 months old, and for the past 2 weeks it's been every nap and every bedtime. He screams and won't go to sleep unless I'm in there. Once he's down at night he'll wake over and over. What is going on???