I guess until your best friends dead mate starts calling him up on the telephone, you don't know or think to investigate the full range of psychological problems that it can bring out. And many people don't knownthey were predisposed to a mental illness until it's too late.
I'm sorry but this one is really close to home for me. There's no way I could be convinced to support this to be legalized under any circumstance.
I too have seen first hand the devastating effects of cannabis use. But the reality is, it is so widely available now that legalising it probably wont change how many people use it, but it will make how it is grown and sold more regulated. If it wasn't illegal, seeking advice and information and support would be much easier. If it was legal then there wouls probably be more education around about the risks of mental illness and cannibis use.

I do think, like alcohol, it can be a dangerous drug, but i don't think it being illegal helps anyone.