[Avodah] Issur in smoking marijuana?

[Moshe Y. Gluck]

R' AM:
> BTW, while we're on this thread, I'd like to thank those who answered my
> question by pointing out that the addictiveness of drugs, and the tendency
to
> hang out with society's lower elements, do make RMF's teshuva apply more
> strongly to drugs than to tobacco and alcohol.

I was speaking with someone about this over Shabbos, who said that she had
no problem stopping smoking marijuana (though she wasn't a heavy user) - is
there any way to measure addictiveness?
Also, on the subject of comparing these three addictive substances, I would
guess that RMF based his Psak on common usage, as his Shittah, I'm told, is
to be Nigrar after the Minhag. Smoking tobacco was accepted so he needed to
justify it, alcohol was accepted. But marijuana was not. The Halachic
process trumping consistency.

KT,
MYG