I am a mother of four children (21, 19, 15 and 15) who have varying degrees of asthma and allergy. All of them have some degree of ADHD as well. The oldest took Singulair from grades 7 to 12. It was great for his allergy, but he had a depression which was attributed to his ADHD.
The second is still taking Singulair. She is highly asthmatic and it has been beneficial for her. The severity of her asthma went down to the controllable range, and her migraines (suffered since second grade) significantly decreased (documented side effect).
The last two, identical twins, began taking Singulair four years ago when they developed asthma as they entered puberty. They became oppositional, defiant, prone to rages, and curiously not hustling hard enough at their sports. Prior to this, they were solid, dependable students, with moments of inspiration - and aggressive athletes, leaders at their sports. We always thought the problems were related to puberty and the ADHD. More and more ADHD meds were applied. No more weekends off the meds - because our house would be destroyed.
As 2008 began, my own allergies flared. When the doc offered Singulair, I looked forward to feeling better. Within 48 hours, I could breathe at night, and the tightness in my chest went away. Even my allergic dermatitis improved.
Then a weird thing happened. I got lazy. I heard myself saying things like, "I don't care if I'm fat." I stopped doing my evening chores. I stopped pursuing my hobbies. I almost stopped making dinner. I was wondering why I didn't care, but I didn't care enough to pursue that, either.
Then it got worse. I couldn't handle the least criticism. I was in tears over almost anything. Within a few days, I was trying to find a way to leave my family. I just didn't care about anything any more.
The water-cooler crowd at work was chatting about the news reports about Singulair and suicide. I started to wonder: gee, doesn't depression preceed suicide? Maybe this hopeless feeling I had was related to the Singulair.
So I stopped taking it. 48 hours later, I started to laugh at jokes again. Five days later, I cleaned my kitchen. Now it's been three weeks and I'm back at my hobbies and loving life.
Two weeks ago, I realized that the never-ending laziness and argumentation we've been getting from our twins might be related to Singulair. I checked with the ADHD doc, and their general doc, and got the go-ahead to discontinue the medicine (although not both of them at once). I did this without telling anyone: not the twins, not my husband, no one.
Forty-eight hours after the first kid had stopped taking the Singulair, I came home to a grinning, hugging, 15 year old, who sat me down at the kitchen table to explain the strategy he'd designed to study for his upcoming exams. I was speechless and numb. I didn't tell anyone that he was no longer taking the Singulair (he takes a variety of vitamins and ADHD meds every day). The next day, my husband called me excitedly: the kid was cooperating with him! He didn't know what to make of it. I kept him in the dark for a few more days.
The other twin had been on a lower dose (5mg rather than 10 mg). I stopped his medication as well. The change in him has been more gradual.
Neither of them takes ADHD medicine now on non-school days. They are happy and cooperative. We ask ONCE for chores. There are still a few arguments and stormy moods - but I no longer wonder what's going to get broken next. And they seem to love working as hard as possible at their sports.
The good news is, we all feel better. The bad news is -- how did this happen? How can it be that such an obvious side effect was missed?
It's not like the effect of montelukast on the brain is unexplored. Try searching on "montelukast brain ischemia" - there are many studies that show that montelukast (Singulair) dramatically reduces brain swelling. What does it do for an uninjured brain? Does it dehydrate it? Deprive it of nutrition? If I had to characterize the behavior I saw in my twins, it's this: they acted the way hypoglycemic patients do, when they're late for their next snack. REALLY GRUMPY.
Or do some research on migraines and Singulair. There's an effect there, too. Many asthma patients on Singulair report that their migraines improve.
So the drug clearly affects the brain, and Merck's position that Singulair doesn't cause suicidal ideation is almost irrelevant. The fact is, montelukast has a significant, often-studied effect in the brain. That effect is not fully understood.
In our house, the effect of montelukast on the brain has been significant. We have dragged two kids to many psychiatric evaluations. We've spent hours and hours with teachers and principals and counselors, trying to understand why they just won't get their work done. We've used every performance-management trick in the books to get them to work - without much benefit. The kids have swallowed an awful lot of stimulant medication because it was the only thing that controlled their rages. Who knows what their teachers think of them - are they forever branded as the lazy kids? And we are lucky. From this forum, I've learned that it could have been a lot worse.