1. Smoking (anything) raises your risk of oral and lung cancers, including marijuana.
So vape it or bake it into cookies or whatever. You don't have to smoke it.
2. Marijuana lowers IQ in developing brains, e.g. children and adolescents. If you've seen the kind of permanent damage neurons experience after smoking marijuana, this is hardly surprising.
Citation pls. Also who says kids should have it? This is for grownups only, same as tobacco and alcohol.
3. Marijuana causes psychosis in healthy people and worsens it in those with existing conditions.
Again Citation needed. We have just barely started to study this. RTFA.
4. Marijuana is addictive. It's a hotly debated point but the fact is that many people really struggle to stop using it and relapse.
No it isn't.It isn't addictive, and the point is not hotly debated. It is as habituating as any other pleasant pass-time, but addictive, in the way a doctor would define it, it is not. Damn near everyone I knew at school who smoked weed, (which is damn near everyone i knew) doesn't smoke any more. It was no big hardship, you just stop. Coffee is actually more addictive, it will give you withdrawal symptoms, marijuana will not. Look at it this way, over 50% of Americans have tried weed, under 5% smoke it daily.