Montelukast
"My daughter has taken this for about 8 years.  She's always seemed to have extreme emotional reactions to the smallest things.  I asked her doctor multiple times if it might be the montelukast she takes causing this.  Dr. said "no, reported side effects just happen when the child starts taking it.  Must just be her personality".  I know what is normal and her reactions were extreme.  Everything came to a head this past winter when she started having obsessions about eternity.  We took her off the montelukast.  About 2 weeks later she had a psychotic break.  She was crying all day saying she didn't want to exist.  It has taken 2 months to get her back to semi-normal.  This drug is not good for children!!!  Her experience is not unusual!"