Fda medical symptoms and conditions

My 6 1/2 year old daughter has been on Singulair for 3 1/2 to 4 years now and we have had horrible experiences! She was having night terrors, mood swings, angry issues, self control issues, crying over small things, etc. We have been to psychiatrists and psychologists who have diagnosed her with mood disorder, sensory processing disorder and anxiety disorder! Well she has recently been having stomach problems so we have been going to a GI to figure that out. I got online to research and found numerous sites that told how Singulair causes all these things in children. We took my daughter off the meds and within 3 or 4 days seen a tremendous difference! She is a totally different child! It just really frustrates me and saddens me that all these children and their families are going through all this and the doctors do not seem to care. The allergist or psychiatrist didn't believe me. They say no study has ever proven such things. I don't care what they say we as parents know our children and we are the experts when it comes to seeing how they change when on this medicine, we are the ones that live with them and are with them everyday not the doctors! I think they just don't want to lose out on their money from prescribing this drug 90% of children with allergies and asthma!