New research in Britain suggests that people who have used cannabis may be 40% more likely to develop a psychotic illness such as schizophrenia.
The study published in the medical journal The Lancet says the drug could be a factor in 14% of young adults who show symptoms of psychosis, such as hallucinations or delusions.
In a Psyciatric Times report last year, Drs Asif R Malik and Deepak Cyril D'Souza found that there is no existing literature that says cannabis causes a persistent de novo psychosis independent of any other risk factors.
They point out that cannabis is a component cause that interacts with other factors (eg, genetic risk) to induce psychosis.
Alcohol and legal medications such as anti-epileptics have also been linked to psychosis.
