"my son is now 13, and has been using concerta the past 2 years. was working great, went from doing homework until 12-1:00 am to finished before i got home from work.  concentrated more and was overall happier with himself and his achievements. around november he had started having trouble sleeping and eating and was acting different. i guess since he turned 13 and puberty is starting to set in it wasn&#039;t working for him anymore so we are changing medications. i do recommend this medicine though, while it worked, it was great."