Skip to main content

Verified by Psychology Today

Coffee Addiction: Is It All in Your Head?

A new study examines how much of caffeine withdrawal is real versus imagined.

Source: nastya_gepp/Pixabay

Anyone who has experimented with alternative diets has probably been through a few caffeine withdrawals. But is there a "best way" to cut coffee from your diet, assuming that's something you want to do?

New research published in the Journal of Psychopharmacology may hold some answers. In this research, experimenters recruited 48 heavy caffeine users (consuming at least 270 mg per day, or three cups of coffee) to take part in an effort to examine how information on dose reductions influence self-assessments of withdrawal severity. In other words, they wanted to understand how much of the caffeine withdrawal process was real versus imagined.

To answer this question, they randomly assigned participants into two groups. Both groups were put on the same caffeine reduction plan over a five-day period. On the first day, participants were given two cups of coffee (one in the morning, one in the afternoon) with a total of 300 mg of caffeine. The second, third, fourth, and fifth-day procedures matched the first, with the exception that caffeine doses were gradually reduced (200 mg, 100 mg, 0 mg, and 0 mg, respectively).

What differed between the two groups was the information participants received about their dose-reduction plan. One group received accurate information about their reduction schedule, while the other group was (mis)informed that they received the full 300 mg of caffeine on the first, second, and third days of the experiment and 0 mg on the fourth and fifth days.

Each day, researchers measured caffeine withdrawal symptoms using the Caffeine Withdrawal Symptom Questionnaire (CWSQ). This 23-item scale measures symptoms such as fatigue/drowsiness, low alertness/difficulty concentrating, mood disturbances, low sociability/motivation to work, nausea/upset stomach, flu-like feelings, and headache.

The researchers then compared the CWSQ scores between the two groups, predicting that caffeine withdrawal symptoms would be more in line with the information participants were given about the doses, not the actual doses they were receiving.

Indeed, this is exactly what they found. The group that received accurate information about their dose reduction showed caffeine withdrawal symptoms steadily increasing throughout the multi-day test period. The group that was misinformed, however, showed flatline CWSQ scores for the first three days and a big uptick on day four. The researchers write, "Given that they received identical doses of caffeine, these day-to-day differences in reported withdrawal can only be explained by differences in expectancies."

Even if expectations are to blame, one question remains: Which group was more accurate in assessing their "true" withdrawal symptoms? Well, there's no way to know for sure, but it's likely that both groups were biased in reporting their symptoms. The group that received misinformation likely fell prey to a "placebo effect"—that is, thinking they were receiving effective treatment when, in fact, none was administered. The group that received accurate information, on the other hand, was likely biased by a "nocebo effect"—manifesting the negative side effects the treatment was known to produce.

What wisdom might this study hold for the next time you try to kick your caffeine habit? For one, it suggests that at least part of your withdrawal symptoms are based purely on your expectations. This knowledge alone might help you imagine a better outcome the next time you quit or reduce your coffee intake. It also suggests that tricking yourself into thinking you are receiving caffeine when, in fact, you are tapering your dose—or, conversely, thinking that you are tapering your dose when you are receiving caffeine—might be the best way to kick your coffee habit. Of course, you'll have to find someone to assist in the deception...

Facebook Image Credit: Ivan_Shenets/Shutterstock

LinkedIn Image Credit: bbernard/Shutterstock


Mills, L., Boakes, R. A., & Colagiuri, B. (2018). The effect of dose expectancies on caffeine withdrawal symptoms during tapered dose reduction. Journal of Psychopharmacology, 0269881118817158.