Schizophrenia / Other Psychoses

 Schizophrenia and other psychotic disorders tend to cause abnormal thinking, or often the individual may lose touch with reality. Psychotic symptoms can be positive or negative. For example, positive symptoms include hallucinations and delusions, but negative symptoms include lack of concentration and inability to show emotions. Substantial evidence shows there is an association between frequent marijuana use and the development of schizophrenia or psychoses. In fact, the more frequently the individual uses marijuana, the higher risk of developing schizophrenia or other psychoses. Some data also support an association between cannabis use history and cognitive performance, and some support an association between cannabis use and the increase in positive symptoms of schizophrenia. However, there is limited support regarding an association between cannabis use and the worsening of negative symptoms.