NO CAUSE-AND EFFECT BETWEEN POT AND MENTAL ILLNESS

While I agree with Frank Sterle Jr.'s contention that there is a lot of
media misinformation about cannabis, I must point out that assertions such
as his -- that "pot-consumers' mental health depends in part on the
reduction or prevention of cannabis consumption" -- are part of the problem
(Pot can exacerbate some mental illness, Letters, April 23).

The study cited by Mr. Sterle reported a positive correlation between
levels of marijuana use and symptom chronicity among schizophrenics. Such
studies can tell us nothing about the cause-and-effect relations between
the correlated terms. Perhaps cannabis worsens schizophrenia, or chronic
schizophrenics are more likely to try self-medicating with marijuana, or a
third factor affects both cannabis use and schizophrenia.

Even if marijuana use does negatively affect schizophrenics, this casts no
light on the effects of cannabis on non-schizophrenics. Public policy on
recreational drugs should be based on a clear understanding of the complex
biological, psychological and social contexts involved, not on
misinterpreted research outcomes.

Dr. Leonard George

Vancouver