Singulair and experience hair

I posted this question in the question section, but wanted to know if anyone else has experienced hair pulling as a side effect. My 10 year old son has been on Singulair for about a year and 3 months ago he started pulling out his eyelashes and eyebrows as well as other body hair ( a disorder known as trichotillomania). He also has been talking about being sad, hating his life, etc. We are worried sick and his self esteem is taking a huge hit due to the hair pulling. He says he is a freak and he hates himself because he can't stop it. We took him off Singulair 2 days ago and are waiting to see if there are improvements in his behavior. Thanks.