Does "drug of choice" define your issue or your circumstance?

People have drugs of choice - that much is obvious. Less obvious are the reasons for particular drugs of choice. There are those who will take any "mind altering" drug they can get their hands on. Yet, more often people want the effects of certain drugs. What should we learn? When the drug becomes the addiction the path out depends upon what the drugs are "saying". Do we listen? Who has thoughts to share?