We’re about to explain something we’ve all wondered, especially during holiday season: Why does being drunk make us want to drink even more? We all know it when we hit that mid-beer-buzz sweet spot—when our senses are keenest, our conversation at its most lucid, our eight-ball skills bordering on miraculous. Yet despite the fact that we know—we know—the next glass will push us into the steady slide from all-conquering hero to lip-flapping squid in constant need of the bathroom, we crave it anyway. Why, nicely-toasted brain, why? Why must you always be thirsty for more?
The answer lies buried in the brain’s nicely-toasted reward pathways. Although alcohol acts as a suppressant in parts of the brain that control physical operations (standing up, having sex, finding keys, or all three at once), it also stimulates the production of dopamine. This devious organic chemical is indeed both dope and mean, as it activates areas of the brain associated with desire and reward. This ‘reward system’ is a set of interconnected structures in the brain that are responsible for our sensations of wanting nice things we don’t have; liking nice things when we get them; and learning that getting them again would be a good thing (a repetitive process known as “positive reinforcement”).
One such reward zone, the ventrial stratium — a pea-sized party nubbin deep in the right hemisphere — has recently been investigated by researchers in Indiana as a potential cause of addiction, both to alcohol and to other habit-forming drugs. Intriguingly, this research also suggests that it’s not just the presence of alcohol in your bloodstream that triggers dopamine activity: Even the first taste of a cold beer can be enough to set your brain’s reward system chugging.
Aside from the motivation-reward effect of dopamine, alcohol also prompts the release of the “feel-good” chemicals known as endorphins. These are associated with the euphoric pleasures people get from laughing or hardcore exercise. For happy drunks, much of the endorphin rush comes from a part of the forebrain called the nucleus accumbens: If the ventrial stratium is the brain’s muttering drug dealer, then this, perhaps, is its soaring gospel choir.
Of the two incentives urging us to pour out another, it seems the darker instinct is stronger than any benign attraction towards our happy place. According to a study published last year in the Journal of Neuroscience, every time you drink a boozy beverage you may be training your brain to want it more next time around. This is because dopamine activates two types of pathways in the brain: “D1” neurons, which encourage proactive behaviour (such as, “Go back to the bar. Now”) and “D2” neurons which inhibit behaviour (“Hey you, you’re at peak beer buzz and charming the pants off the room: DO NOT drink any more”). While the latter seems like it would be more useful to us, alcohol predominantly lights up the D1 pathways, referred to by lead researcher Jun Wang as the “let’s do it” neurons.
The really unfortunate thing is that this “Vegas, baby, yeah!” moment somehow sticks in our brains as the part that’s most enjoyable about drinking in the first place. “When you drink alcohol, long-term memory is enhanced, in a way,” Wang commented around the time the study was published. “But this memory process is not useful — in fact, it underlies addiction since it affects the ‘let’s do it’ neurons.”
Sensible neurons, your cab’s here. We’re just going to hang out with these crazy guys for a little while longer. See you in the morning for hangover, fried food and remorse!