“Caffeine has a calming effect on the ADHD brain. The theory is that the brain of people who suffer from the disorder has an overabundance of dopamine transporters, or re-uptake inhibitors. They carry away dopamine too fast, creating a shortage of it. In turn, that affects serotonin and norepinephrine. The combined effect is a reduced ability to focus, especially on tasks that the person doesn’t enjoy, a lesser ability to control impulsivity, and it even messes with the awareness of time. Caffeine stimulates dopamine production in the brain, temporarily filling up the gap created by the rapid”