text: Ritalin (stimulant) works because it stimulates a certain part of the brain to work at a minimum level of activity to control other parts of the brain. It only is really effective in this way in people whose executive function area is already working below normal. It doesn't do the same thing with people who are  'normal'. It only speeds them up, but only at dosages above the ADD/ADHD levels which are usually used. There are other side effects of using stimulants, like insomnia, indigestion, dry eyes....