As I stated in an earlier post, my 3 year daughter takes Singulair and my 7 year old son took it until December 2007. I've been concerned about my daughter but after reading some of these posts I now wonder if this drug was impacting my son negatively. For the past year and a half/two years, he was waking up several times a week due to horrible nightmares or night terrors. He would cry out and when I would get to him his hair would be ringing wet. Although he would talk to me, he never made any sense but he was scared to death. He would never remember the episode the next morning. It's been months since he had an episode and I mentioned to a friend a few weeks ago that he seemed to have finally gotten through that phase. After reading these posts, it makes more sense. He stopped taking Singulair in December!