The Association Between Cannabis Abuse and Subsequent Schizophrenia: A Swedish National Co-Relative Control Study

Cannabis abuse may make an individual more vulnerable to having schizophrenia.

This study investigated the abuse of cannabis in relation to the subsequent development of schizophrenia. Researchers followed more than 20,000 Swedish men and women, monitoring their health and lifestyle. 

Researchers discovered that cannabis abuse (CA) heightened the odds of developing schizophrenia. This study concluded that "CA has an appreciable causal impact on future risk for schizophrenia."