Yes, and I have lost a number of friends the same way. All smoked pot, then it graduated either to hard drugs, combinations of alcohol & uppers or prescriptions to alleviate their anxiety attacks. And some morons still think weed is not harmful.
You know that teaching someone to fish is better than serving one up to them. Feeding the hungry is wonderful and important, but teaching them a skill that can keep them from ever being hungry again is far better.