Dopamine And Drug Addiction
Originally it was thought that dopamine was simply a precursor molecule to make a different chemical in the norepinephrine, that is closely related to adrenaline, the ‘fight or flight’ molecule. So, it was just thought that it was an intermediate step, not important one. But everything changed in 1957 when Dr. Carlsson showed that dopamine was a neurotransmitter (a chemical the brain uses to process information) in in its own right and not just a precursor of norepinephrine.
Nowadays it is known that dopamine is one of the most important neurotransmitters in the brain responsible for an unbelievably broad variety of behaviors in human beings. A lot of people have heard about dopamine as the pleasure molecule and that’s one thing it does. Dopamine was originally made to make us desire things that will benefit us evolutionarily and reward us when we do it. Eating when you are hungry, drinking when you are thirsty, reproduction, winning competitions – these are natural things.
As the professor and psychiatrist Daniel Z. Lieberman says, the reason why drugs are so dangerous is because they short-circuit these survival pathways. They hijack the dopamine system and instead of gently stimulating it, like winning a competition would or eating a nice meal, they slam it with a chemical blast that outweighs any natural behaviors. Our brain develops priorities in large part based on how much dopamine it is going to get.
The Molecule of More: How a Single Chemical in Your Brain Drives Love, Sex, and Creativity – and Will Determine the Fate of the Human Race
For example, on the legendary Russian show ‘The Field of Wonders’ (‘Pole Chudes’) deciding what do you want – 10 thousand rubles or what’s behind the door number 2 (there’s a good chance that behind this door is a car or something), people would probably choose the 2nd option that’s going to give more dopamine. So, drugs artificially stimulate this circuit and produce more dopamine than any other natural behavior.
As we see a poor guy out on the street who’s lost his family, job, home and money because of his drug addiction, we tend to think that it’s completely irrational to do that. But from the inside – the human brain, it’s absolutely rational for him, because he is choosing the bigger dopamine. It is just as rational as to give 10 thousand rubles for the door number 2 – it feels like the right thing to do.
What makes it so tough to get off of drugs is because of two things – reward and punishment.
- The reward is that when you take it not only dopamine is stimulated but other different kinds of pleasure molecules as well. Dopamine is a rush of pleasure, it’s a pleasure you feel when you’re excited or enthusiastic about something (for example, when you score the soccer goal).But there’s also a different type – contentment pleasure, when you feel like everything in the world is perfectly fine. And such heavy drug as heroin can give you both of these kinds of pleasure.
- The punishment is that if you get addicted to it and then you stop using it, you go into horrible withdrawal having painful and terrible experience.
If you want to learn more about dopamine and its influence on human brain, I would highly recommend you to read ‘The Molecule of More’ by Daniel Z. Lieberman, MD and Michael E. Long.