Hi my husband says he was seen by a doctor who would recommend using marijuana for his various mental and physical ailments...however I ve read of research that shows that marijuana has been shown to cause mental illness although there is contracting evidence as well apparently. I was wondering he says that when used in small amounts that rather than it bogging down the system it actualy enhances the body and mind function such as more alertness, better mental processing, etc. Is there any real proof of any of this.