How Dopamine Reward System Addictions Work

Have you ever tried a drug? Perhaps you think not, because today when we talk about drugs we want to refer to psychoactive substances or those that produce certain hallucinogenic effects, but what if I told you that there are drugs that are normalized and present in our day to day life?

Well yes, and you may already know what I am referring to. Alcohol and tobacco are two drugs whose consumption in our society is (too) normalized, but that it is normalized does not mean that it is not dangerous and that it does not generate addiction.

What if you decide to try some drugs with your friends? Because, total, for once nothing is going to happen, right? But what if one time is followed by another, and then another, and another? Well, in the end, the repeated use of this drug generates an addiction in your body, a dependency that makes you become a slave to that substance . Unfortunately, in addition, some drugs are capable of subduing us with just one dose.

How does addiction work?

Addiction is basically wanting something so badly that you can’t help but act on it, often to the detriment of your health . First of all, the addictive substance in question captivates your brain by giving it pleasure, and later, it begins to corrupt your normal drives, such as motivation and learning. That’s what makes cutting your addiction such a challenge, whether it’s alcohol, tobacco, other drugs, or sex. Let’s delve into how addictions work…

What is the dopamine reward system?

Some of the main drugs that cause addiction are opioid pain relievers (narcotics), marijuana, and cocaine. When someone uses drugs on a regular basis, their brain stops performing normal functions and begins to release more dopamine than usual , changing brain chemistry, eventually blocking the reuptake of dopamine. This can cause a feeling of euphoria and happiness for a long period, so it will become “the new normal” of our brain, and it will ask us for more and more of that pleasant feeling.

These substances also produce tolerance. Tolerance to a substance occurs when, as a result of its continued administration, the subject has less sensitivity to it. Thus, the usual dose of the substance produces fewer effects, so higher doses are needed to produce the same effects. Thus, you will be hooked on increasing and unsustainable doses to achieve those effects that your brain now craves. You won’t be able to think about anything else, or enjoy other activities. The normal functioning of your brain has been altered and now everything else seems boring and monotonous. You are now an addict, and that is how the cycle of addiction works.

But what was responsible for controlling pleasure was not dopamine? Does dopamine have something to do with all this? Yes, the dopamine reward system plays an important role in the sensation of pleasure that is achieved after consuming a drug, a fundamental pillar of the trap that the cycle of addiction supposes.

When we talk about the reward system we are referring to those rewarding stimuli that produce certain actions in our body. The consumption of addictive substances can activate this reward system. These are the brain functions that drive the essentials of being human, like sleep, eating, pain unawareness, and reward, of course. Anything that leads to human learning , motivation , and pleasurable feelings could be a reward. However, the reward system is a group of structures that help our brain calculate the value of the reward and translate it into actions.

Dopamine is a neurotransmitter , and it increases the brain’s response when exposed to a rewarding stimulus. Thus, structures connected to the reward system are present along dopamine pathways in the brain. Basically, what happens is that the neurons that make up the reward system communicate through dopamine in different regions of the brain . For example, getting technical, the mesolimbic dopaminergic pathway connects to the ventral tegmental area (VTA) . In other words, one of the dopamine pathways, one of the neural streams that it runs through, connects to one of the central dopamine-producing areas in the brain. That dopamine-producing area, the VTA, in turn communicates with another area, the nucleus accumbens . The nucleus accumbens , in turn, connects to another area, the ventral striatum, and has a strong connection to reward and motivation . Therefore, when these neurons communicate with the nucleus accumbens , motivational and reward behavior is more likely to be processed. Now you surely understand better the concept that the dopamine reward system is actually a set of structures interconnected with each other, through dopamine.

Another important pathway for dopamine is known as the mesocortical pathway , which travels to the cerebral cortex from the VTA. It is believed to be part of the reward system. Therefore, research shows that major dopamine pathways, including the mesolimbic pathway and structures such as the nucleus accumbens and VTA, play important roles in producing a reward system. This is how the dopamine reward system works .

It would be reasonable to ask why this system exists in us, if it makes us so vulnerable to some substances. However, it is an essential system . The main functions of the dopamine reward system are to produce associative learning (with an important role in affecting decision making) and to induce approach behavior by eliciting emotions with positive value (pleasure, enjoyment,…). As we mentioned before, it is the system that rewards us with motivation, learning and other pleasant stimuli.

What does science say about the reward system?

Rewards simply help motivate us to do something. For example, if someone offers you $500 to bring your pet home, you are more likely to do so. Or if your parents offer you a mobile phone as a reward when you get good grades, you are more likely to get better grades. Similarly, our brain has its own reward system that finds pleasure and rewards us by giving us pleasurable sensations.

Several studies show that the alteration of the reward system of our brain makes us more prone to psychiatric disorders . For example, an important node in the brain’s reward circuitry, the lateral habenula , appears to inhibit the release of dopamine to encode punishment. Disorders with inappropriate anger and aggressiveness are associated with dysfunction in this area. Furthermore, the stimulation of regions of the amygdala leads to the triggering of aggression and indignation . Research shows that inappropriate activation of the reward system in the brain leads to psychiatric disorders and violent social stimuli.

Dopamine is a pleasurable neurotransmitter, but responses vary from person to person. It is closely associated with the reward system that enhances human motivation and reward behavior. However, it is necessary to keep the reward system balanced. Otherwise, it can lead to psychiatric disorders, such as depression, schizophrenia, bipolar disorder, etc. This is because when a person seeks pleasure and avoids pain for too long, but relies on drugs for artificial pleasure when their own dopamine is not enough, the risk of intense depressive behavior is very high. Therefore, even for this, or perhaps especially for this, it is very important to maintain a balance in the functioning of the dopamine reward system.

A more complex question is why do people take drugs in the first place?

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