"Add"? Marijuana is here and has been for a few decades. The primary effect of widespread legalization will be to take profits out of cartel hands - and redirect them to legal businessmen who will card minors as illegal dealers never do.
I was speaking in 1960s-ish
But now that you mentioned it . . No, the primary effect will be Fng up another generation of kids under the guise of “legalization” and “it’s no more harmful than alcohol”
Interesting isn’t it, how young people are the victims of childish adults and their careless selfishness and BS.
See drugs and HIV/AIDS for examples