CANNABIS AND MENTAL ILLNESS

Sir, The Advisory Council on the Misuse of Drugs (ACMD) considered in some
depth possible links between cannabis and mental illness (report, January
21) and concluded that there is little significant evidence of a causal
link, particularly with schizophrenia, although cannabis use can
unquestionably worsen a mental illness which already exists.

Most of Professor Robin Murray's research was known to the advisory council
at the time it was producing its cannabis report. The council is of the
view that any new evidence produced since does not affect the overall
weight of evidence, or its conclusions about health risks.

You quote Professor Murray saying: Unfortunately there were no experts in
psychosis on the committee that advised the Government,implying that our
report was not a comprehensive study. ACMD members are drawn from a wide
range of backgrounds and areas of expertise.

Both the sub-committee meetings of the ACMD, and the full council meetings
at the time of the discussion on cannabis reclassification, were well
attended by representatives from the fields of psychiatry and
psychopharmacology.

As far as I am aware, the BMA has not taken an official position on
reclassification. However it has raised concerns over the public perception
of the health effects of cannabis. The classification system for drugs does
not mean that any of these substances are harmless. If they were, they
would not be included in the Misuse of Drugs Act.

Yours faithfully, MICHAEL RAWLINS, (Chair), Advisory Council on the Misuse
of Drugs, 50 Queen Anne's Gate, SW1H 9AT. January 21.