Can you tell me that cannabis smoke contains chemicals which may cause mental illness in some people?

Yes - that is true.: Possible effects of marijuana: anxiety, depression, fear, panic , delusions, paranoia, hallucinations, losing touch with reality, inattentiveness, short-term memory problems, disturbances of thought processes. Fatigue, poor concentration, slowed reaction times ; slowed problem solving.

Pot + mental illness: The latest research I have read suggests smoking marijuana may not cause schizophrenia or unipolar or bipolar depression. However, if one is already genetically predisposed to these illnesses it could speed up the development of the disorders.