The illusion of coffee consumption: Caffeine acts against withdrawal effects - and can trigger anxiety

Coffee, tea and energy drinks: Worldwide people consume caffeine to be awake in the morning or in the evening to keep fit. Who can accompany the coffee machine through the day, used to it quickly to the effects - and must reckon with short withdrawal with fatigue, headache and loss of concentration. In people with a particular gene variant nature drug caffeine can even trigger anxiety. A research group in Bristol, London, Würzburg and Münster has the relationship between caffeine, anxiety and attention, habituation effects and genetics now investigated.

"A regular caffeine consumption seems mainly to counteract the negative effects of withdrawal," Dr. Christa Hohoff of Münster University, a lead author of the study. 379 people attended. A half of them usually consumed little or no caffeine, the other half of the consumption was in the mid to high range - converted at least about one cup of coffee a day. 16 hours all participants fully waived caffeine. Then they were either caffeine or a placebo and determines the perceived levels of anxiety, attention and headaches.

"A few years ago, with the participation of researchers from Münster, it could be demonstrated that a genetic variant in the adenosine A2A receptor has an impact on the perceived fear," explains Hohoff: "The caffeine mainly docks on the receptor in the human brain." In the current study, the biologist examined the different receptor variants in the Molecular Psychiatry Laboratory at the University Clinic for Psychiatry and Psychotherapy. The study confirmed that people with a certain genetic makeup are more affected by caffeine in their fear. Apparently, this does not stop them from consuming it: on average, the test subjects with the special receptor variant consume even more caffeine. This in turn leads to habituation and thus a decrease in the feeling of fear.

If the study participants with higher caffeine consumption were given a placebo after the 16 hours of withdrawal, they reacted with a headache and significantly reduced attention. Caffeine, on the other hand, prevented headaches and at the same time raised awareness - but only up to the basal value, i.e. to the level that the study participants with lower consumption had in the placebo condition anyway. Hohoff believes that regular caffeine consumption primarily counteracts the withdrawal effects: whoever drinks coffee or tea does indeed become more attentive, but only in relation to their lower starting level than regular consumers. It is an illusion that caffeine increases awareness permanently. Hohoff is particularly interested in the question of the extent to which genetics influence the human psyche - as in the fear effects observed here. Despite the study results, she doesn't do without her morning coffee: "I like the feeling of invigorating effect, you have the illusion of being more attentive."

The study has now been published in the renowned journal "Neuropsychopharmacology". The original article entitled "Association of the Anxiogenic and Alerting Effects of Caffeine with ADORA2A and ADORA1 Polymorphisms and Habitual Level of Caffeine Consumption" is available on the Internet. Further information on this work as well as current research focuses and a number of further publications can be found on the website of the Laboratory for Molecular Psychiatry.

Literature:

Rogers P. et al. (2010): Association of the Anxiogenic and Alerting Effects of Caffeine with ADORA2A and ADORA1 Polymorphisms and Habitual Level of Caffeine Consumption. Neuropsychopharmacology advance online publication 2 June 2010; doi: 10.1038 / npp.2010.71

Source: Münster [mfm / tw]