Is d-methamphetamine a dopamine agonist? Seems like it increase dopamine when i google. I have a colleague who can speak very well. However she seems to be overactive hyperactive usually like schizophrenia psycotic dopamine overloaded and she can speak very well and does not stutter. Just wondering is it lack of dopamine or over dopamine that causes the stuttering? As you said methamphetamine cured your stuttering but it increases dopamine. How does methamphetamine affect the brain? Methamphetamine increases the amount of the natural chemical dopamine in the brain. Dopamine is involved in body movement, motivation, and reinforcement of rewarding behaviors. The drug’s