Pubdate: Wed, 25 Jun 2014
Source: Las Vegas Review-Journal (NV)
Copyright: 2014 Las Vegas Review-Journal
Website: http://www.lvrj.com/
Details: http://www.mapinc.org/media/233
please. Send them to  Kate Kelland, Reuters
Page: 9A

STUDY EXAMINES GENE LINK BETWEEN CANNABIS USE, SCHIZOPHRENIA

LONDON - Genes that increase the risk of a person developing
schizophrenia may also increase the chance they will use cannabis,
researchers said on Tuesday after studying more than 1,000 users of
the drug.

The results chime with previous studies linking schizophrenia and
cannabis, but suggest the association may be due to common genes and
might not be a causal relationship where cannabis use leads to
increased schizophrenia risk.

Cannabis is the most widely used illicit drug in the world, and its
use is higher among people with schizophrenia than in the general 
population.

"We know that cannabis increases the risk of schizophrenia. Our study
certainly does not rule this out, but it suggests that there is likely
to be an association in the other direction as well - that a
pre-disposition to schizophrenia also increases your likelihood of
cannabis use," said Robert Power, who led the study at the Institute
of Psychiatry at King's College London.

Schizophrenia is a common and severe psychiatric disorder that affects
around one in 100 people.

People who use cannabis are about twice as likely as those who do not
to develop it.

The disorder typically begins in late adolescence or early adulthood
and its most common symptoms are disruptions in thinking, language and
perception. It often includes psychotic experiences, such as hearing
voices or delusions.

While the exact cause is unknown, research to date suggests that a
combination of physical, genetic, psychological and environmental
factors can make people more likely to develop it.

Previous studies have found a number of genetic risk variants
associated with schizophrenia, each of which slightly increases a
person's risk of developing the condition.

Cannabis use has frequently been associated with it, but there is much
debate about whether this is because of a direct cause, or whether
there may be shared genes that predispose people to both cannabis use
and schizophrenia.

A study published in March 2011 found that people who use cannabis in
their youth dramatically increase their risk of psychotic symptoms.
The study also noted that continued use of the drug can raise the risk
of developing a psychotic disorder in later life.

And earlier research found that young people who smoke cannabis for
six years or more are twice as likely to have psychotic episodes,
hallucinations or delusions.

This latest study was published on Tuesday in the journal Molecular
Psychiatry.
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