ADHD experts express markedly similar opinions on a variety of topics, but coffee consumption creates a great divide. Some warn that caffeine should be avoided, because it is an inferior stimulant that can disrupt and confuse the effects of prescribed medications. Others consider it perfectly acceptable, as long as individuals keep in mind that it is a weak stimulant and may interact with their other medications.

We have a wealth of data showing that caffeine can boost alertness and attention and reduce reaction times in the general population. Researchers have also conducted numerous studies in rodent models of ADHD, showing positive effects on some executive functions. But most of the human ADHD research is simply observational, documenting high levels of coffee consumption for many with ADHD. Most of the studies that administered doses of coffee or caffeine to those with ADHD were completed forty to fifty years ago, and had amazingly small numbers of subjects.