As a college student, I am no stranger to late nights, early mornings, seemingly endless work, and not enough time to do it all. What’s the result of this? We prioritize the work over sleep and rely on coffee to get us through the day. I never really understood how caffeine works, I just remember growing up watching my mom drink a cup of coffee everyday and knowing that adults drink it because they are tired. I tried to avoid drinking coffee for as long as I could because I knew that caffeine dependency was a very real thing, and I did not want to struggle with having to stop drinking coffee. How does caffeine affect the brain? For starters, we know that it makes us more awake and alert, but what really goes into it?
In a study done testing the effects of caffeine on the brain, twenty healthy male controls (38±8 years of age, body mass index 26±3; years of education 14±2) who drank less than two caffeinated beverages per day, caffeine was found to increase striatal dopamine D2/D3 receptor availability in the human brain. Caffeine, as most of us know, is the most widely consumed psychoactive substance in the world. Caffeine works by enhancing dopamine signaling in the brain by antagonizing adenosine receptors. Using positron emission tomography and raclopride (a D2/D3 dopamine receptor sensitive to dopamine with an internal origin) to determine if caffeine had an influence on the amount of dopamine released in the striatum of the participants. The results demonstrated that caffeine drastically increased the availability of D2/D3 dopamine receptors in putamen and ventral striatum (the brain regions indicated in the image below). Caffeine does not increase the amount of dopamine in these brain regions, it increases the amount of dopamine receptors available to process these neurotransmitters.
What does it mean when dopamine receptors are able to process more neurotransmitters? Caffeine is so effective because it is meant to increase alertness and decrease tiredness. Comparisons were made to determine if this was actually true, and the behavioral effects of a placebo and of caffeine were recorded before, at 30 minutes, and at 120 minutes after being administered. As can be seen from the charts below, caffeine not only improves feelings of energy, but it also improves overall mood when compared to the placebo’s effects.
Based on the results provided by the study, it can seem like a good idea to continue to rely on coffee and other caffeinated drinks to improve mood and energy levels, however, this also makes it a dangerous substance. Caffeine addiction forces the brain to be reliant on the production of dopamine receptors to increase alertness, mood, sleepiness, and tiredness, so it stops producing these receptors on its own. This is the same reason an increase in tolerance occurs. A recent medical has shown that caffeine is strongly addictive and can result in symptoms of intoxication, withdrawal, and dependence. When you have been a regular coffee drinker and go one day without coffee, you may notice some of the withdrawal symptoms which include: headaches, fatigues, difficulty concentrating, increased feelings of anxiety, tremors, irritability, and depressed mood.
Knowing this, I do not want to become caffeine dependent. Although I will continue to enjoy my occasional cup of coffee from Blue Donkey or Starbucks, I know that I am better off trying to find other energy uplifting activities. Caffeine may be beneficial in the short term, but the benefits of good sleep will always outweigh the temporary benefits of caffeine.
- Volkow, N., Wang, GJ., Logan, J. et al. Caffeine increases striatal dopamine D2/D3 receptor availability in the human brain. Transl Psychiatry 5, e549 (2015). https://doi.org/10.1038/tp.2015.46
- Kubala, Jillian. “8 Symptoms of Caffeine Withdrawal.” Healthline, Healthline Media, 24 Apr. 2018, www.healthline.com/nutrition/caffeine-withdrawal-symptoms.
- Olekalns, Nilss, et al. “Rational Addiction to Caffeine: An Analysis of Coffee Consumption.” Journal of Political Economy, 1 Oct. 1996, www.journals.uchicago.edu/doi/abs/10.1086/262054?journalCode=jpe.