Singulair and math

Hi, I have written on this forum before. Our son (6) was on Singulair for over 3 years for Asthma. Over those years, his whole personality changed; it happened so slowly, however, that we assumed that those changes were "phases". We stopped Singulair 16 days ago, and we have seen big changes in our son. Thus, I want to summarize our side effects by describing the changes in my son:
Suddenly no more fears (nightly waking up scared to death, and fear of being alone in any room in the house during the day), sleeping through the night, less agitated and less aggressive, better listening skills (again!) and more interest in learning (this was a child that once loved science and did math at age 3. He lost interest in anything that had to do with learning). He draws happy faces again. He is also less nervous. He lets us hug him again, and tells us how much he loves us.
Some days are better, some days are worse. There are times he still tells me that he wants to "throw himself in the trash" and other negative things about himself and his life. We also still see obsessive compulsive behavior (a tic where he touches his head and then his legs from his feet up, driving me crazy), but it is slowly getting less severe. But overall the changes are very clear.
As for the Asthma: we still use Flovent once a day: so far we had no setbacks. Our doctor noted the side effects, but was rather surprised about them. Obviously, I will NOT EVER give my children Singulair again, no matter what the doctor will tell us.

My son has been on Singulair for over a year now, and I'm beginning to wonder if the medicine is what his problem is. He's in the third grade, and is struggling really bad in Math. He also has little tantrum fits, and doesn't seem to listen as I think he should. I'm having him tested for a learning disability, but I just wonder if it's the medicine? He was put on it for the Chroop, he seems to get it really easy, and I'm afraid to take him off for fear he might get the Chroop again. I don't really know what to do.
Concerned Mom`