True, but assuming that the damage has a cumulative effect, over the long term it seems that pot has definite potential to be a damaging substance.
No one ever talks much about the psychologically-damaging effects of dope, which is the main reason I oppose its legalization. It takes a vigorous, active, get-it-done sort of person and turns him into an apathetic vegetable.
I suspect, for example, that's the ultimate destiny of the maudlin waif primitive.
When I was in college, one of my roommates was a computer whiz and a musical genius (classical), and got great grades all the way up to his junior year. But then unfortunately he got turned on to dope by, of all people, my best friend from back home.
It took several months, but he changed. He no longer cared about computers or music or anything else; all he did was smoke dope.
It was a harrowing sight, watching a person decline like that.
About a year after he was hooked, out of the blue, he joined Reverend Moon's Unification Church, and became a Moonie. He was in that cult for about four years the last time I heard from him (which was a long time ago now). I have no idea what he's up to these days.