Placebo caffeine reduces withdrawal in abstinent coffee drinkers

Abstract

Background: Expectancies have been shown to play a role in the withdrawal syndrome of many drugs of addiction. However no studies have examined the effects of expectancies across a broad range of caffeine withdrawal symptoms, including craving. Aims: The purpose of the current study was to use caffeine as a model to test the effect of expectancy on withdrawal symptoms, specifically whether the belief that one has ingested caffeine is sufficient to reduce caffeine withdrawal symptoms and cravings in abstinent caffeine drinkers. Methods 24-h abstinent regular coffee drinkers completed the Caffeine Withdrawal Symptom Questionnaire (CWSQ) before and after receiving decaffeinated coffee. Half the participants were led to believe the coffee was regular caffeinated coffee (Told group) and half were told that it was decaffeinated (Low Expectancy group). Results: Participants in the High Expectancy group reported a significantly greater reduction in craving, fatigue, lack of alertness and flu-like feelings factors of the CWSQ than those in the Low Expectancy. Conclusions: These results indicate that the belief that one has consumed caffeine can affect caffeine withdrawal symptoms, especially craving, even when no caffeine has been consumed.