Nice article! As a former drug addict,
I can definetely comfirm these points.
There are 2 things I want to mention:
Make sure to never push your kid in a corner and confront it about the drug abuse in a harsh manner. It will just lead to stronger consum behavior. Try to see the drug problem as the tip of the iceberg and try to solve the problem hat causes the drug abuse. If your kid is just trying out weed for example, leave it alone! It's just curious, don't push it into being a real drug abuser.
They way your kid spends money is one of the most alert factors. If they are out of money very fast and ask you constently for more, it's an important sign!
Peace out=)