“Cannabis and psychotic illness” Sane Australia. Retrieved 2.13.08 – “Does Cannabis cause psychotic illnesses like schizophrenia? Use of Cannabis can cause a condition called Drug-induced psychosis. This usually passes after a few days. However, if someone has a predisposition to a psychotic illness such as schizophrenia, these drugs may precipitate the first episode in what maybe an ongoing condition. There is increasing evidence that regular cannabis use precedes and causes higher rates of psychotic illness.
How does Cannabis affect someone who has a psychotic illness? Cannabis generally make psychotic symptoms worse and lower the chances of recovery from a psychotic episode. People with a psychotic illness like schizophrenia who use such drugs experience more hallucinations, delusions and other symptoms; they have a higher rate of hospitalisation for psychosis, treatment is generally less effective and recovery more difficult.
So should people with a psychotic illness avoid drugs like Cannabis? Yes. The consequences can be so serious for the person’s health that it is best to avoid drugs such as Cannabis completely. It can be helpful to look at other, healthier ways of relaxing and socialising as an alternative.”