In a recent study, researchers found that frequent coffee drinkers showed an increased ‘wanting’ for coffee without an increased ‘liking’ for coffee — a dissociation that is characteristic of the development of addiction. The findings were published in the Journal of Psychopharmacology.
Caffeine is a psychoactive substance that is regularly consumed by many people around the world. Although caffeine addiction is not currently listed in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), researchers Nicolas Koranyi and his team say that caffeine dependence shares certain similarities to drug addiction. For example, some heavy coffee drinkers experience unpleasant effects with high consumption and yet struggle to limit their caffeine intake. Moreover, those who do quit caffeine can experience withdrawal symptoms.
Koranyi and his team conducted a study to explore whether heavy caffeine use follows a similar mechanism as drug dependence. A theory called incentive-sensitization theory (IST) says that addictions are maintained by two separate processes — a motivation for the reward, deemed ‘wanting’, and the enjoyment of the reward, called ‘liking’. It is proposed that in the development of addiction, as the involved brain areas become more sensitized, ‘wanting’ increases while ‘liking’ decreases.
While past studies on this topic have used self-report measures of ‘wanting’ and ‘liking’, Koranyi and his colleagues instead used an Implicit Association Test (IAT). These tasks ask participants to match stimuli to certain categories by pressing a key on a keyboard while their response times are measured. The tests are used to assess subconscious associations between concepts and attributes.
The experiment involved 56 university students who were either heavy coffee drinkers (three or more cups each day) or low coffee drinkers (one or fewer cups each day). The participants completed two IAT tests — one designed to assess their ‘liking’ for coffee and the other their ‘wanting’.
The analysis revealed that heavy coffee drinkers showed significantly higher ‘wanting’ for coffee than low coffee drinkers did. However, ‘liking’ for coffee was the same among the two groups. Moreover, an assessment designed to measure characteristics of caffeine use disorder predicted participants’ ‘wanting’ for coffee but not their ‘liking’ of it.
As the authors say, their study is the first to show that heavy coffee drinkers demonstrate a disconnection between ‘wanting’ and ‘liking’, mirroring the motivational processes believed to underscore addiction to other drugs. This suggests that caffeine mimics the characteristics of other drugs, with ‘wanting’ being the driving force behind its consumption more than ‘liking’.
Still, the researchers say that caffeine is far less addictive than other substances, and not many coffee drinkers would meet the criteria for dependence.
“It seems likely that the extent to which the wanting system becomes sensitized is much lower in caffeine compared with other drugs,” Koranyi and team note. “However, with regard to the underlying motivational and neurophysiological processes involved in dependence development, the main difference between highly addictive drugs (e.g. alcohol or cocaine) and substances with lower addictive strength (e.g. caffeine) may mainly be a quantitative rather than a qualitative one (Dill and Holton, 2014).”
The study, “Dissociation between wanting and liking for coffee in heavy drinkers”, was authored by Nicolas Koranyi, Elisabeth Brückner, Andreas Jäckel, Laura Anne Grigutsch, and Klaus Rothermund.
