Hello, this is Dr. Alexandra Gidoiu. Vyvanse is an amphetamine, a stimulator and gives you more energy and produces weight loss. This is a dangerous drug to be taking without prescription. I would not advise it. This drug also has addictive properties. I suspect your brother has ADHD? Perhaps you are also experiencing the same symptoms as him. You should go see your doctor and if they make the proper diagnosis and prescribe you the Vyvanse then you can take it, otherwise not. This medication has a positive effect on those with ADHD, however on those who are normal, it can destroy the normal chemistry within the brain, and in the lond run this may produce disorders and mood instabilities. I would suggest to try other methods for your lack of concentration at school such as, engaging in sports activities with your colleagues. This will improve your mood, improve your confidence, and give you energy, plus the other endless benefits of exercise. You could also try to concentrate on a subject at school which you really like. I dont know your age, but if you are old enough i would suggest also drinking coffee to boost you up.