The Most Effective ADHD Medication For Adults Most ADHD medications are classified into two categories: stimulants and nonstimulants. The stimulants like methylphenidate (Provigil) and amphetamines work by increasing activity in parts of the brain that regulate the behaviour and attention. Nonstimulants, such as atomoxetine (Strattera), Guanfacine (Intuniv) and Clonidine (Kapvay)
