RECLASSIFICATION OF CANNABIS WILL PUT ADDED PRESSURE ON NHS

Sir: The Conservative leader is being quoted as stating that he would
reverse the decision of this government to reclassify cannabis to a class C
drug (report, 22 January). We are concerned that the imminent
reclassification of cannabis has not taken the most recent evidence into
account.

Over the past few years, our knowledge of the adverse impact of
cannabis on mental health has increased substantially. There is
considerable clinical evidence linking cannabis use to mental illness,
especially schizophrenia, psychosis, anxiety and depression. The risk
of developing mental illness, especially psychosis, is increased with
earlier and heavier cannabis use.

A person who uses cannabis by age 15 has more than a four-fold
increased risk of developing schizophrenia symptoms over the next 11
years compared with a person starting to use cannabis by age 18.
Eighteen-year-olds who have used cannabis 50 times have a nearly
seven-fold increased risk of developing psychosis over the next 15
years. Up to 80 per cent of new cases of psychosis currently seen in
some psychiatric hospitals are triggered by cannabis abuse.

Psychiatric services, especially in London, are near crisis point due
to cannabis-induced mental illness. Over the past three decades, a
doubling of the prevalence of schizophrenia has been observed in
London. While it is too early to say whether this is due to the
increase in cannabis abuse over the past decades, this possibility
cannot be discounted on current evidence.

In addition, cannabis has significant negative effects on intellectual
functioning, including learning, concentration and educational
achievement. Furthermore, there is increasing evidence linking
cannabis to road traffic accidents and violent crime. There is
increasing evidence on the adverse physical effects of smoking
cannabis. Three to four cannabis cigarettes are as damaging to the
airways as 20 nicotine cigarettes day. Severe lung damage due to
bronchitis and emphysema, but also head and neck cancers have been
observed in young cannabis users.

We believe that further research needs to be carried out to establish
the exact impact that increasing cannabis abuse will have on the
health service, especially on mental health and accident and emergency
services as well as the criminal justice and educational systems. We
are concerned that the imminent reclassification of cannabis will send
out the message that cannabis is harmless and legal, thereby
increasing cannabis abuse with all the adverse effects on an already
overstretched NHS.

Dr CLARE GERADA Director of drugs training programme, Royal College of
General Practitioners London SW7

Professor HEATHER ASHTON Division of Psychiatry, University of
Newcastle

HAMISH TURNER Immediate past President, Coroners Society of England
and Wales Torquay

Dr HANS-CHRISTIAN RAABE

Leigh, Lancashire