The dopamine seesaw.
Our brain fights to restore the balance of dopamine in our brains.
In our brain we have a balance system, like a seesaw in a playground. When we experience pleasure it tips one way, when we experience pain it tips the other.
One of the fundamental rules is that it wants to remain level. So, with any deviation from neutrality the brain will work very hard to restore balance (homeostasis).
For example, having a piece of chocolate (or glass of wine etc) will provide a tip to the side of pleasure and a release of dopamine, but as soon as that’s happened our brain adapts to that phenomenon by downregulating our dopamine receptors and transmitters, a little like a gremlin hopping on the pain side of the seesaw to balance it out.
The challenge with the gremlin is they like the balance, and they stay on there until balance is tipped in equal and opposite amounts to the side of pain - called the opponent process reaction (hangover or comedown). This is the moment we want another piece of chocolate, glass of wine etc.
If we wait long enough, the gremlin hops off and balance is restored, but if we continue to consume in ever larger amounts to overcome the tolerance (i.e. number of gremlins on the pain side), then the gremlins multiply and we’re in a dopamine deficit state with the balance of the seesaw tipping to the side of pain.
Now we need to keep drinking not to feel good, but just to feel normal and, when we stop using, the balance tips hard to the side of pain and brings on irritability, anxiousness, bad sleep, and so on - i.e. withdrawal.
I heard this explanation on a podcast I was listening to by the guest, Anna Lembke, MD at Stanford, and loved how it had been simplified. I hope you do, too.