Activity schedule symptoms and conditions

My daughter was prescribed Singulair in the spring and it worked wonders.Since her allergies and asthma don't bother her in the summer I took her off for those few months.Since she has been back on the last few months I notice once and awhile an aggression/depression behavior.I thought immediately that it was Singulair causing this but it wasn't everyday it happened.I believe that activity,schedule,and even food in combination with this medicine that was cause this rare effect.It's no news to parents that all of these things can change a persons attitude and behavior.I also believe that Singulair may just make people more sensitive to their true self as my daughter has always been paranoid and has lacked self esteem.I think that it is trial and error as with any medicine.Try it and it may or may not work for you.Taking it off the market would be a disgrace as it has saved many lives.