In the last article, we explained how weed commandeers the brain’s reward system. Read that article if you haven’t yet. Recap: The fun begins when the THC in marijuana blocks inhibitory neurotransmitter gateways by disguising itself as anandamide, the so-called bliss molecule. Without inhibitory neurotransmitters blocking the dopamine gateways, dopamine comes down like candy from a pinata that Barry Bonds has taken a swing at. When the dopamine is flowing like that, we feel intense pleasure. And intense pleasure slams our go system into fifth gear. This happens for two reasons. Firstly, there’s so much more dopamine than normal floating around that the brain reinforces marijuana use in a much more intense way than it does for plain old survival behaviors like sex and eating. So instead of just encouraging us in a supportive way to go and get more like it normally does, our go system begs for weed like a teenager begging for the wifi password from her mom. And secondly, the stop system’s hands have been tied. Without these tiny bouncers patrolling around our brain to shut stuff down before it gets too out of hand, the dopamine just keeps on flowing. So what’s wrong with that, you ask? Well, our body is basically one big thermostat. All of our systems, especially our neurological system, are continuously making fine-tuned adjustments so that our body never gets too far from a state of equilibrium. We are always being gently directed towards homeostasis. Always. And bombarding the brain with dopamine is not a matter of making a slight recalibration here or there. The brain has to compensate in a major way for what it perceives as scary, random, flash floods of dopamine.
Homeostasis Dials Down the Release of Dopamine
So how does the brain handle the five-alarm scenario it thinks the situation is? It does something very logical: it reduces the amount of dopamine released into the brain. What this amounts to is that when a user is stoned, less dopamine flows than once did. But you know what really sucks? There’s now less dopamine flowing even when the user is sober. Of course, you can simply increase your THC consumption to compensate for the reduced amounts of dopamine. And this may work for a while, but then the brain just compensates again. This cycle of increasing usage and dosage keeps the user one step ahead of the game until, that is, the brain eventually catches up. The thing is, this cycle really screws the user because the brain has all this while been dialing down the level of dopamine circulating in the brain when there is no THC present. And this is a very, very bad thing.
Weed and Low Dopamine Levels
Dopamine is the stuff that allows us to feel pleasure. You don’t want any fewer, not even one molecule fewer, dopamine molecules doing their happy thing in your brain. The inability to feel pleasure is a major bummer. It’s a symptom of depression, and lo and behold depression has been linked to people who have lower-than-normal dopamine levels. Contemplate the distinct possibility that weed could spirit you away to dopamine-shortage land, at least temporarily.
In conclusion, we see that the last thing in the world that anyone wants is an across-the-board decrease in dopamine levels. Almost everything we do—consciously or subconsciously—we do to increase our dopamine levels. There’s no doubt that weed mucks with the brain’s reward system. But there’s a silver lining to all this: A recent study says that marijuana probably doesn’t cause dopamine levels to decrease permanently. (They’re pretty sure, though, that other drugs can lower dopamine levels permanently.) So if you quit smoking marijuana, your dopamine levels will eventually bounce back to normal. That is a wonderful thing.