There is hardly a substance that is completely good or completely bad, and those that cause worse consequences are not only illegal. Just as there are the equivalent of some psychodrugs sold in herbalists as "natural products", there are legal psychoactive substances that create addiction and potential harm, such as alcohol. Ingesting a large amount of calories through alcoholic beverages can lead to less nutrition, so much so that there is a specific dementia very serious due to chronic alcoholism that appears precisely as a result of the lack of a vitamin (B). Yet as fundamental as vitamins are, an excess of vitamin C, for example, can cause kidney stones.

Life always remains a matter of subtle balances, where there is no "right" and one "wrong", it simply has to be related to the rest. The balance breaks easily if we no longer choose on a criterion what is good for us and what is not; this is precisely what happens when we become slaves to something whether it is coffee, tranquilizers or an affective relationship.

Not only from heroin, therefore, you can be addicted, but from the most varied things: shopping, sex, gambling, etc. Addiction breaks a balance and makes that gesture live as an obsession that becomes less and less pleasant than at the initial stage.

What remains pleasant is that the moment you take on or do what you crave, you stop suffering. For example, cigarettes contain activating substances such as nicotine, when a smoker turns on one he should therefore feel more activated, yet it is the simple gesture of turning it on that makes him feel more comfortable. The reason for this is that it temporarily suppresses a shortcoming. When something really likes it, a kind of transformation takes place in the brain level. If something attracts us so much and there is a big gap between the well-being that gives us in one moment and the malaise that gives us at another time, it reinforces a part of the brain called the "reward circuit" and creates addiction.

Addiction is therefore a complex phenomenon in which the characteristics of the object of pleasure and those of the person interacting with us are intertwined. Some substances quickly induce heavy physical and mental dependence, such as opioids, while others give a very strong psychic dependence, such as an inadequate affective relationship. As far as psychoactive substances are concerned, however, there are intermediate steps between independence and addiction: use and abuse. Use concerns a controlled and limited consumption of a substance. Tolerance concerns the necessary amount of the substance to achieve the desired effect; this quantity is gradually increasing.

Many drugs quickly induce tolerance so from use you quickly switch to abuse and/or addiction. People who have developed a tolerance to a substance tend to take increasing doses to achieve the same effects: this is a first sign of danger to addiction. Abuse concerns improper or excessive consumption which becomes less and less controllable and, if prolonged over time, quickly falls into addiction. Those who are addicted to something or someone are part of the problem, which is why it is very difficult for them to manage their situation without the outside help of a professional.

Addictions have a strong impact on the quality of life, as well as economic. For example, affective addiction leads to increasing depression because you expect your partner to do something you won't be able to give. The great advantage of quitting smoking or eliminating any other addiction is freedom.