I am a high functioning schizophrenic.
I have used weed on occasion.
I found that, while it makes you paranoid, it also helps relieve anxiety that happens due to schizophrenia.
If common sense prevails against overuse, then it is helpful.
I could believe that it might detour cancer if administered in the right way.
If it makes you cough, its probably not good for the lungs.
Edibles and vaporizers seem to be the best way to administer since you are not taking in smoke from the plant material.
too much thc without cbd causes a state similar to schizophrenic symptoms and clearly can cause damage.
here is a video that shows the effects of pure thc compared to thc with cbd.
https://www.youtube.com/watch?v=6U8XARojnbM