Some research suggests that a minority of moderate regular caffeine consumers experience some amount of depression, anxiety, low vigor, or fatigue when discontinuing their caffeine use.[140] However, the methodology of the these studies has been criticized.[138] Withdrawal effects are more common and better documented in heavy caffeine users.[citation needed]

About 15% of the U.S. general population reports having stopped drinking coffee altogether, citing concerns about their health and the unpleasant side effects of caffeine.[141]