Substance Addiction: Tolerance And Abstinence
We will all have heard of substance addiction, tolerance and the withdrawal syndrome. But what exactly do these terms mean?
In general terms, addiction disorder applies to all those substances that, once introduced into the body, condition or alternate the mood and conduct of the individual. Among these we can find legal drugs, such as alcohol or tobacco, or illegal substances, such as cannabis, cocaine, LSD, etc.
Today we have staggering data on the prevalence of psychoactive substance use. From the age of 15 onwards, 91% of the population consumed alcohol and 64% tobacco. It is even more worrying if we look at the consumption of substances between the ages of 14 and 18: 66% consumed alcohol in the last month and 37% tobacco.
Some key aspects to understanding why substance addiction occurs are the processes of tolerance and withdrawal. They are closely related to each other, as they result from the compensatory response of the body. But first we need to understand what happens to the brain when we use drugs.
Substance use and reward system
Most psychoactive substances are highly related to the brain’s reward system and dopamine. Dopamine is a neurotransmitter that is secreted when we perform desirable behaviors and has the function of reinforcing them to repeat them in the future. Basically, dopamine is the “reward” the body gives us in the form of pleasure for doing something it deems good.
Drugs cause or even go so far as to simulate dopamine production in our reward system. Some of them, like alcohol, do this by indirect mechanisms, while others, like amphetamines, have a similar chemical composition and behave like dopamine.
This false production activates our reward system. A set of mechanisms that allow you to associate certain situations with a feeling of pleasure. In this way, the brain believes that consumption is beneficial to the body, despite the fact that it is actually harmful.
These large “false dopamine” discharges also cause a severe imbalance in the individual’s homeostasis. All this leads the body to activate its regulatory mechanisms to regulate this phase shift, the latter being the cause of tolerance and withdrawal syndrome, processes that we explain below.
Tolerance and withdrawal syndrome in substance addiction
The body’s regulatory mechanisms, to prevent internal imbalance from occurring, regulate brain chemistry. Substance consumption is an example of just that. Let’s see what it consists of.
Imagine that every Saturday night you go out to party and have a few glasses of any alcoholic drink. Since alcohol is an endorphin-mimicking drug, your endogenous opioid system will be hyperactive and secreting dopamine and producing a rewarding sensation. If you repeat this course, your body will learn it and generate a compensatory response.
This is when drug tolerance comes into play. The next Saturday you go out, your brain will know from the start that you will consume alcohol and this will cause an imbalance, lower the basal levels of endorphins. This will depress your endogenous opioid system, but after drinking the alcohol it will return to normal. Your subjective feeling will be that alcohol has no effect on you and that you need to drink more to compensate for the compensatory lowering of tolerance.
What happens if you suddenly stop drinking? What happens to this compensatory response? Although you have reduced or eliminated consumption altogether, the compensatory response continues to occur. If we go back to the example above, then, when you go out on a Saturday with no intention of drinking alcohol, the brain will think so, since that is what it has learned. Your endorphin level will drop precipitously and, not being compensated by alcohol ingestion, will cause you excessive anxiety. This process is known as the withdrawal syndrome.
Conclusion
Tolerance and withdrawal syndrome are unambiguous symptoms of a substance addiction disorder. If tolerance starts to appear, there will also be abstinence when you stop consuming that particular substance you are addicted to. In addition, the onset of withdrawal syndrome usually prompts the person to consume the substance to reduce the anxiety caused by stopping the intake. These biological mechanisms need to be considered to understand substance addiction processes.
Substance addiction disorder is a global health problem. It is necessary to be aware of the multitude of social, work, personal and health problems it causes. Furthermore, if we want to improve the quality of life of people, it is essential to bring to light the mechanisms of action of drugs to make the population aware of the risks involved in their consumption.
