The magic is not in drugs, but in mind control.
The society has been organized since time immemorial in order to form and educate slaves. A necessary condition for this is the formation of a neurotic psyche with many prohibitions, complexes and unconscious restrictions. In modern society, this task is successfully solved by a kindergarten, school, university, and for boys also by the army.
Unfortunately, our parents and ourselves, as parents of our children, make a huge contribution to this, but this time through ignorance, not purposefully.
A person is internally free, forming his own ethics and morality, rationalizing its own fears and complexes, does not need a narcotic intoxication. In the society of such people, any drug, including alcohol, is completely devalued. For in nature it is difficult to imagine cockroaches that would be thrown off on dichlorvos.
Unfortunately, this is an unattainable social ideal, like communism around the world. But realizing this concept in a separate private life is real.
The answer is very simple - pleasure and enjoyment that a person cannot get from real life (this is in most cases).
Someone only needs to smoke one cigarette to calm down and put their thoughts in order, someone does not. Also, one of the reasons may be an oversupply of material resources, i.e. drugs as a means of entertainment. A person who has always had enough in life is looking for new sensations, feelings that he has never experienced.
And it so happens that they resort to drugs out of despair; not to have fun and not to seek new sensations, but to make the situation even worse, these are individuals who were subjected to excessive control from their parents or constant humiliation, accompanied by statements such as "you will not achieve anything in life, you are not independent, you do not know how to solve problems, you are nothing not standing. " Yes, there is a type of people who, after such statements, on the contrary, strive for the best and work on themselves; they want to prove they are worth more. And there are desperate ones - "if I am not good for anything and my life is so insignificant, then why not. It will not be worse, and if it does, then who cares".
But still the most important reason is the inability to cope with life's problems. It is unlikely that from a good life people begin to ruin themselves like this.