DRINK AND DRUG ABUSE 'IS IN THE GENES'

People who take illegal drugs, drink or smoke may be partly at the
mercy of their genes, according to a new study.

Research into more than 20,000 people has shown that genetic factors
strongly influence personality traits linked to unhealthy lifestyles.

Scientists at Cancer Research UK and Oxford University pooled data
from 46 studies into the links between behaviour and genes, and
focused on key genes that control neurotransmitters - the chemicals
that pass messages between brain cells.

They found that one version of the human serotonin transporter gene,
5HTT-LPR, was strongly associated with anxious personalities. People
with this gene variant were more likely to find social interaction
stressful and seek refuge in drinks, tobacco and drugs.

They also identified a weaker link between a variant in a second gene,
the dopamine D4 receptor, and extrovert personality traits. People
with the gene variant are more likely to smoke or take drugs.

Dr Marcus Munafo, who led the research, said: "Our study suggests that
there's a genetic basis to certain kinds of personality trait, which
may be important in influencing whether people take up habits like
smoking or whether they can subsequently give them up."

The findings were published in the journal Molecular
Psychiatry.

Scientists do not know why particular gene variants influence
personality but have some clues. The 5HTT-LPR variant influences
levels of serotonin activity. Serotonin helps control emotions such as
anxiety and depression.

Variations in the dopamine D4 receptor alter the brain's response to
dopamine, a signalling molecule associated with novelty seeking
behaviour and pleasure.

Professor Robert Souhami, of Cancer Research UK, said: "Around half of
all cancers are potentially preventable if people were to alter their
lifestyles, so finding ways of changing behaviour is one of our key
priorities.

"This research suggests that some people are particularly prone to the
kind of unhealthy lifestyles that we know can be a cause of cancer.
These people may be resistant to conventional health messages and may
need subtler health warnings, or perhaps specific anti-addiction
treatment for their particular personality type."