It is not convincing either person...
drugs are just bad...
I have a very old friend of mine that was a bad father, scammer, hit his wife and kids, and never worried about their lives only himself, till he quitted doing drugs, hes been clean for about 12-13 years now. and he is a complete different person. now don't come here and try to convince me drugs are good or they altered your percepcion of things cos drugs just screw things up in your head.
the first way of fixing any problems with yourself and others is juts accepting you got one.!
Post-Modern Consumerism is just bad. Alcohol is just bad. Diplomacy based on a highest end of a structured hierarchy is bad. Pretty soon, you will find out most of what our world is today is composed of 'bad' things, badly executed and badly controlled with a tremendous leap of information. The point being?
The point is that drugs, just like any other thing in our world, will always resume unhealthy is no information, control and right execution are had. I speak of experience --nearly 60% of my family has been addicted to alcohol, 80% have been addicted to some kind of drug and presently 50% still are. I've seen them at their worst just as I have at their best --with or without the effect of drugs. Some people change for better. Others for worse. For as much as our human consensus would love to pick on these specific cases and ground a general pattern to them, it just isn't doable.
I've drugged myself. I have posted as much in this community whilst in the effect of drugs as I have without. Coherence has never been issue, most certainly. My ideals have remained developing and healthy --That is because I very much like to control my liking to drugs, because I have read about each and every drug I've taken...because I'm aware and have myself that way. Most importantly, because I don't drug so I can escape into a fantasied world of my own --I'm not running away from anything, just having fun and enjoying the treats drugs may bring forth.
Your friend may have been unluck. Or your friend may have not been as responsible as I am. Don't take offense to any of what I am saying. Just be clear that drugs aren't the issue; the issue is how we, humans, behave with them and why we take them for. Just like any other thing in life. It all depends on how we deal with them.