Boojum
01-26-2004, 12:16 PM
I've put this in politics cos a lot of politicians are still using the myth of causal links betwwen pot & schizophrenia. This is the latest research into the links (and you'll see the conclusion is that there aren't any).
Testing hypotheses about the relationship between cannabis use and psychosis.
Degenhardt L, Hall W, Lynskey M.
National Drug and Alcohol Research Centre, University of NSW, NSW 2052,
Sydney, Australia. [email protected]
AIM: To model the impact of rising rates of cannabis use on the incidence
and prevalence of psychosis under four hypotheses about the relationship
between cannabis use and psychosis. METHODS: The study modelled the effects
on the prevalence of schizophrenia over the lifespan of cannabis in eight
birth cohorts: 1940-1944, 1945-1949, 1950-1954, 1955-1959, 1960-1964,
1965-1969, 1970-1974, 1975-1979. It derived predictions as to the number of
cases of schizophrenia that would be observed in these birth cohorts, given
the following four hypotheses: (1) that there is a causal relationship
between cannabis use and schizophrenia; (2) that cannabis use precipitates
schizophrenia in vulnerable persons; (3) that cannabis use exacerbates
schizophrenia; and (4) that persons with schizophrenia are more liable to
become regular cannabis users. RESULTS: There was a steep rise in the
prevalence of cannabis use in Australia over the past 30 years and a
corresponding decrease in the age of initiation of cannabis use. There was
no evidence of a significant increase in the incidence of schizophrenia
over the past 30 years. Data on trends the age of onset of schizophrenia
did not show a clear pattern. Cannabis use among persons with schizophrenia
has consistently been found to be more common than in the general
population. CONCLUSIONS: Cannabis use does not appear to be causally
related to the incidence of schizophrenia, but its use may precipitate
disorders in persons who are vulnerable to developing psychosis and worsen
the course of the disorder among those who have already developed it.
Testing hypotheses about the relationship between cannabis use and psychosis.
Degenhardt L, Hall W, Lynskey M.
National Drug and Alcohol Research Centre, University of NSW, NSW 2052,
Sydney, Australia. [email protected]
AIM: To model the impact of rising rates of cannabis use on the incidence
and prevalence of psychosis under four hypotheses about the relationship
between cannabis use and psychosis. METHODS: The study modelled the effects
on the prevalence of schizophrenia over the lifespan of cannabis in eight
birth cohorts: 1940-1944, 1945-1949, 1950-1954, 1955-1959, 1960-1964,
1965-1969, 1970-1974, 1975-1979. It derived predictions as to the number of
cases of schizophrenia that would be observed in these birth cohorts, given
the following four hypotheses: (1) that there is a causal relationship
between cannabis use and schizophrenia; (2) that cannabis use precipitates
schizophrenia in vulnerable persons; (3) that cannabis use exacerbates
schizophrenia; and (4) that persons with schizophrenia are more liable to
become regular cannabis users. RESULTS: There was a steep rise in the
prevalence of cannabis use in Australia over the past 30 years and a
corresponding decrease in the age of initiation of cannabis use. There was
no evidence of a significant increase in the incidence of schizophrenia
over the past 30 years. Data on trends the age of onset of schizophrenia
did not show a clear pattern. Cannabis use among persons with schizophrenia
has consistently been found to be more common than in the general
population. CONCLUSIONS: Cannabis use does not appear to be causally
related to the incidence of schizophrenia, but its use may precipitate
disorders in persons who are vulnerable to developing psychosis and worsen
the course of the disorder among those who have already developed it.