With the offshoring of manufacturing jobs men with nothing to do end up taking drugs. In poor areas drug use is very common, so it is easy to eventually give in and try it, then you are hooked the first time and can't stop.
https://www.therecoveryvillage.com/heroin-addiction/faq/addi...
that introductory experience can be the start of a compulsive cycle that quickly leads to addiction.
Probably better sources, but the boogeyman scare tactics taught to children to keep them from experimenting with drugs is too simplistic and flawed - but hey no one is going to explain to kids how brain chemistry works because abstinence is ... easier.