I don't think you can score schizophrenia as a direct result of weed smoking, but if you have psych problems laying dormant just under the surface, I'd say it could very well set them off. But it sounds like you're safe. I'd be more worried about winding up completely drug-fucked after 10 years straight of smoking everyday. Nobody wants to end up like Ozzy Osbourne. Minus the money and fame, of course.

Peace