British scientists analysed symptoms of 757 subjects, who developed schizophrenia, of whom 182 (24 percent) had used cannabis in the year prior to first presentation to a psychiatrist due to the disease. There were no significant differences in the symptoms between cannabis users and non-users that have been observed in some small studies. In addition, cannabis users who developed schizophrenia had no greater family history of schizophrenia. The authors concluded that this "argues against a distinct schizophrenia-like psychosis caused by cannabis." (Source: Boydell J, et al. Schizophr Res 2007 Apr 24; [Electronic publication ahead of print])