So you took someone already troubled and made him a drug addict. Dealers do it every day. It's so common.
A man I knew years ago had a friend of his give him pot to make him feel better after his mother died. It was the drug addict form of grief control. That didn't end well. He moved on to pot laced with angel dust and became quite violent.
I won't try to influence your
Reefer Madness orientation because I can tell it is firmly embedded. But for the benefit of those who might be swayed by it, you should understand that because of the number of Americans who regularly use marijuana (estimated at 50 million by NIDA and the DEA) if marijuana were addictive every street in America would by now be inhabited by nodding, stupefied junkies.
The simple fact of the matter is marijuana is
not addictive, nor is it harmful unless consumed to pathological excess, nor is there a single example anywhere in the annals of medical science of anyone having died or been made sick from marijuana, nor is it possible to "overdose" on marijuana.
I don't expect you to take my word for any of that, but if you are at all interested in educating yourself on this subject I will recommend the following books to you:
The Emperor Wears No Clothes, by Jack Herer. And,
Marijuana, The Forbidden Medicine, by Dr. Lester Grinspoon, MD, PhD, Professor of Psychiatric Medicine, Harvard Medical School. Both are available from Amazon.
But if you prefer to remain brainwashed and ignorant, that's your business.