"i am 17 and have been taking this since 8th grade. i was diagnosed because i would get into trouble all the time and when i first started taking it, it was great. i stopped getting into trouble and so on. now, 4 years later i feel it is completely different. rapid heart rate, anger, don&#039;t care mood, dizziness, but it still makes me focused. i&#039;m tying to get off it, but making slow progression because i&#039;m really adhd, my friends concur. the crash after taking it for so long feels like dementia. i only take it on weekdays and could relate to insomnia because i getless than 30 hours of sleep a week. "