What happens to your brain on caffeine?

Coffee is cited as the “most widely used psychoactive substance in the world” with it’s effects akin to cocaine1.
Is caffeine really that powerful? What actually goes on in your brain after a cup of coffee?

A study carried out by the Marshall Space Flight Centre in Alabama may provide a clue to the extent caffeine affects the brain2.
The basis of the study went something like this: they took a bunch of house spiders, fed them drug dosed flies and observed the webs they spun. The idea was that the more mental clarity the drug gave them, the better the spider’s webs should be.
The results looked like this:

your brain on caffeine web

I’ll let you judge these webs for yourself.

Chemically, caffeine is an alkaloid, falling in the same category as cocaine, nicotine, codeine & morphine3. It is safe to say that, however we look at it, caffeine affects the brain.
If you’ve ever had a large coffee, or just a very strong one, you’ll know that it can make you jittery, nervous and in some cases trigger anxiety. Best case scenario, you’ll turn this into some incredible productivity and carry out everything really quickly until the effects wear off.

your brain on caffeine meme

Worst case scenario, you go to your doctor and they diagnose you with a caffeine induced psychiatric disorder. Yes, these exist, there are a total of 4 medically recognised psychiatric disorders associated with caffeine4.
It is safe to say that whoever invented these “disorders” probably doesn’t enjoy coffee (or they accidentally gave their kids caffeine and live to regret the decision).

So what happens in the human brain?
Caffeine blocks adenosine, a chemical that is the signal for tiredness5.

So far so good, except if you overdo the caffeine, your brain just makes more adenosine receptors. Not to mention that the actual effect of coffee wears off in a couple of hours.
The net result is that you either chain drink espressos (not recommended) or you end up more tired than you initially expected.

Luckily there are some clever researchers that figured out a way to cheat this system: coffee napping6.

your brain on caffeine infographic

Would you like to know more about what else happens in the brain after caffeine intake? Comment below and if it is popular enough we will add more of the research.


  1. Daly JW, Holmen J, Fredholm BB (1998) Is caffeine addictive? The most widely used psychoactive substance in the world affects same parts of the brain as cocaine. Lakartidningen, 95:5878-5883.
  2. Noever DA, Cronise RJ, Relwani RA (1995) Using spider-web patterns to determine toxicity. Life Sciences, 19: 82.
  3. Ashihara H, Sano H, Crozier A (2008) Caffeine and related purine alkaloids: Biosynthesis, catabolism. Phytochemistry, 69: 841-856.
  4. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Text Revision (DSM- IV-TR). Washington, DC: 2000:212-5, 708-9.
  5. Addicott MA, Yang LL, Peiffer AM, Burnett LR, Burdette JH, Chen MY, Hayasaka S, Kraft RA, Maldjian JA, Laurientia PJ (2009) The Effect of Daily Caffeine Use on Cerebral Blood Flow: How Much Caffeine Can We Tolerate? Human Brain Mapping, 30: 3102-3114.
  6. Reyner LA, Horne JA (1997) Suppression of sleepiness in drivers: combination of caffeine with a short nap. Psychophysiology, 34: 721-725.