BEFORE ANYONE rages i would like to say i marijuana isn't bad for you it MAY cause short term memory loss for heavy users. Im still at school (Uni) and i want to smoke Marijuana what is safe amount of consumption that will not affect or impair ANYTHING. How many times per year and safe on the growing brain as the brain stops growing when you are a little older than 21 i two relatives with issues. One has Schizophrenia on my moms side and one has brain damage ( Addiction to cocaine and heroin)on my fathers side . Will this have any impact on my brain thanks.