title: Withdrawal syndrome after the double-blind cessation of caffeine consumption.
abstract: BACKGROUND
  People who stop consuming caffeine may have symptoms, but the incidence and severity of caffeine withdrawal are not known. This study was performed to determine the effects in the general population of ending one's dietary intake of caffeine.
  
  
  METHODS
  We studied 62 normal adults whose intake of caffeine was low to moderate (mean amount, 235 mg--the equivalent of 2.5 cups of coffee--per day). They completed questionnaires about symptoms and tests of their mood and performance when consuming their normal diets (base-line period) and at the end of each of two two-day periods during which they consumed caffeine-free diets and under double-blind conditions received capsules containing placebo (placebo period) or caffeine (caffeine period) in amounts equal to their daily caffeine consumption.
  
  
  RESULTS
  More subjects had abnormally high Beck Depression Inventory scores (11 percent), high scores on the trait scale of the State-Trait Anxiety Inventory (8 percent), low vigor scores (11 percent) and high fatigue scores (8 percent) on the Profile of Mood States, and moderate or severe headache (52 percent) during the placebo period than during either the base-line period (2, 0, 0, 0, and 2 percent, respectively; P less than 0.05) or the caffeine period (3, 2, 2, 0, and 6 percent; P less than 0.05). More subjects reported unauthorized use of medications during the placebo period (13 percent) than during the caffeine period (2 percent, P = 0.017). Performance of a tapping task was slower during the placebo period than during the base-line and caffeine periods (P less than 0.01).
  
  
  CONCLUSIONS
  Persons who consume low or moderate amounts of caffeine may have a withdrawal syndrome after their daily consumption of caffeine ceases.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21224.
authors.forename: K
authors.initials: K
authors.lastname: Silverman
authors.forename: S M
authors.initials: SM
authors.lastname: Evans
authors.forename: E C
authors.initials: EC
authors.lastname: Strain
authors.forename: R R
authors.initials: RR
authors.lastname: Griffiths
mesh_terms: D000328:Adult; D002110:Caffeine / Q000008:administration & dosage / Q000009:adverse effects*; D003863:Depression / Q000209:etiology; D004032:Diet; D004311:Double-Blind Method; D005260:Female; D006261:Headache / Q000209:etiology; D006801:Humans; D007406:Interview, Psychological; D008297:Male; D011581:Psychological Tests; D011597:Psychomotor Performance; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology* / Q000523:psychology; D011795:Surveys and Questionnaires
chemical_list: D002110:Caffeine