The study, directed by O’Neill, et al., compared response to cocaine for adolescent rats versus adult rats following regular caffeine consumption. The study found that chronic caffeine consumption in adolescent rats increases chemical signaling in reward centers of the brain in response to cocaine use while chronic caffeine consumption in adulthood elicits little to none of the same effects. Adolescent caffeine use enhances cocaine’s psychostimulant effects and increases likelihood of future engagement in cocaine-seeking behaviors. Caffeine consumption at a young age (i.e. before the brain has fully matured and developed) may thus ‘prime’ the brain for future illicit drug use.
Although the study involved rats, “we know that rats and humans share similar brain structures and neurochemical pathways related to reward processing”*, according to lead author Casey O’Neill, “so it is reasonable to expect a similar effect in young adults.”*
To establish whether the observed behavioral responses had any corresponding physical changes in the brain, the authors tested the brain chemistry of the rat subjects, and found that adolescent caffeine consumption clearly caused enduring changes. Investigation measured increased numbers of chemical receptors in reward centers of the brain resulting from sustained caffeine use. More chemical receptors allow for greater drug response. This suggests that caffeine strengthens chemical signaling pathways and consequent response to psychostimulant drugs, such as cocaine.
This study suggests that caffeine consumption in adolescence may lead to future drug abuse. The difficulty is caffeine has become a staple in the American diet. Increasingly, caffeine has become a common component of the adolescent diet. In one form, coffee, caffeine plays a role in adolescent social life. Meeting for coffee is a typical social outing not only among adults, but also among teenagers and college-students. When caffeine consumption is so ingrained in American social culture, caffeine-limitation among adolescents seems challenging.
Future research studies are needed to understand the particular consequences of adolescent human caffeine consumption. Until then, it may be prudent for parents to discourage caffeine use in children and for young adults to moderate their caffeine use. Your morning coffee may be up to no good.
References:
Neill, C. E. O. A., Levis, S. C., Schreiner, D. C., Amat, J., Maier, S. F., & Bachtell, R. K. (2015). Effects of Adolescent Caffeine Consumption on Cocaine Sensitivity. Neuropsychopharmacology, 40(4), 813–821.
Kendler, et al. (2006). Caffeine intake, toxicity and dependence and lifetime risk for psychiatric and substance use disorders: an epidemiologic and co-twin control analysis. Psychology Med.
Frary, et al. (2005). Food sources and intakes of caffeine in the diets of persons in the United States. J Am Diet Assoc.
Temple, et al. (2009). Caffeine use in children: what we know, what we have left to learn, and why we should worry. Neuroscience and biobehavioral reviews.
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