My son who is 5 years old was on Singulair for 5months. He turned into a total different child. He developed extreme OCD, anxiety, excessive crying, scared at night, and irritability. After researching I found out it was the Singulair causing his symptoms, so I immediately took him off. After just a couple of days his mood lightened. It took a few weeks for the anxiety and OCD to go away, but it did thank God! Although, the main debilitating symptoms went away he still after 5 months is irritable and takes offense to anything and everything. It is like every time I talk to him I say something wrong and it annoys him or makes him mad. Our relationship is completely different now. It is like we are not as close. This was not my son before Singulair. I am heart broken. I read peoples post and most say after taking their children off Singulair all the symptoms went away and their children are back to normal. I feel there is 20% still missing after 5months of being off Singulair. My son is not 100%. I am beginning to feel like he may never be 100%. I feel like it causes some permanent damage. Does anyone else feel the same? Or have a similar situation? Or have still experienced recovery past 5months? I would love to hear your story. THANKS!!