Con
Martin Frisher, PhD, Senior Lecturer in Health Services Research at Keele University, et al., stated the following in their Sep. 2009 article titled "Assessing the Impact of Cannabis Use on Trends in Diagnosed Schizophrenia in the United Kingdom from 1996 to 2005," published in Schizophrenia Research:
“Based on literature suggesting a) an elevated risk of developing schizophrenia/psychosis among cannabis users, b) a substantial rise in cannabis use in the UK from the mid-1970s onwards and c) an assumed elevated risk of 20 years, this model would predict a corresponding increase in schizophrenia/psychosis during our study period [1996-2005]…
The results of this study indicate that the incidence and prevalence of diagnoses of schizophrenia and psychoses in general practice did not increase between 1996 and 2005…
This study does not therefore support the specific causal link between cannabis use and the incidence of psychotic disorders…”
Sep. 2009