I've been an irregular pot smoker for many years, not starting until after college. It has not been a gateway drug for me, but has not helped with the family curse of depression either. Therapy and medication certainly have.
That is not genius news. If you smoke tobacco or drink regularly your whole life, that will mess you up too. Marijuana is a gift from god, growing in ditches all over the world. It has its place like everything else, and has definitely made my life much better.
I smoke very little these days, but I sure as hell enjoy it and will not stop (except within a month or so of when my wife and I get pregnant). Each one of us is different and each one of us must be aware of our own needs and frailties. There are no clear answers to the difficult questions in life, so don't tell me you know what is best for me. Only I can decide that, and yes, I will take responsibility for my choices.