Though stimulants do not always cause anxiety, many create a stress response that could worsen existing symptoms. People with anxiety might not need to stop using stimulants entirely, but they may want to avoid frequent use, especially if symptoms worsen.
Caffeine is the stimulant least likely to cause anxiety. Ideally, 100–200 mg of caffeine should be paired with an equal dose of theanine, an amino acid that can tame the anxiety caused in some people by caffeine without impairing caffeine’s stimulatory effect. In fact, the improvements in concentration (focus and attention span) induced by caffeine and theanine respectively have been shown to be synergistic.
Yohimbine and yohimbine-containing products — as well as supplements that have a similar mechanism, such as rauwolscine — should be avoided.