You’re right. Poor living conditions(whatever this means) may bring you to use drugs to feel good. After the high ended you might want to feel good again(even if it maybe is just 5 days later) so you get high again. Once you start getting high periodically you’re fucked. Eventually the time between each high shrinks. If you use Alcohol(which is a depressant) you will start drinking after it ended, because it make you feel like shit.

People who have a good living condition don’t get addicted to drugs as easy as people with poor living conditions do.