Pubdate: Sun, 22 Feb 2015
Source: Mail on Sunday, The (UK)
Copyright: 2015 Associated Newspapers Ltd.
Author: Stephen Adams, Health Correspondent


BRITAIN'S brightest teenagers are among those most at risk of mental 
illness caused by smoking a potent form of cannabis, a leading expert 
has warned.

Professor Sir Robin Murray said it tended to be 'clever and sociable' 
youngsters who were damaged by using the super-strong strain of the 
drug, known as skunk.

Sir Robin, the foremost authority in Britain on the effects of 
smoking cannabis, led a landmark study with colleagues at the 
Institute of Psychiatry which found that regularly smoking skunk 
triples the risk of psychosis, as revealed last week by The Mail on Sunday.

Now he has given further alarming warnings after his study was 
published in full in The Lancet Psychiatry. Speaking yesterday, he said that:

Skunk now dominates Britain's cannabis market - and is so widely used 
that it has become a gateway drug to tobacco.

It is having a devastating impact on mental health - leaving some 
people with permanent schizophrenia.

Cannabis has been 'effectively decriminalised' in South London.

Teens are now legally purchasing ultra-strong synthetic cannabis 
online - without knowing it is even more likely than skunk to trigger 
psychosis and acute paranoia.

Sir Robin said: 'Twenty-five years ago, if parents, brothers or 
sisters of a patient with schizophrenia asked me: "Could it have had 
anything at all to do with the cannabis he smoked?", I'd have said: 
"There's no evidence that's the case  don't worry about it." All the 
medical journals said cannabis was a safe drug. But now we know there 
are these risks.'

He said: 'A lot of people who develop schizophrenia have had problems 
since they were children. Maybe they had more personality or 
cognitive difficulties than their brothers or sisters. But the ones 
who develop psychosis associated with cannabis, they tend to be 
people who were doing very well.

'Their parents always say: "No I never worried about them at all - 
they had lots of friends, were good at school, good at sport."

'In some ways their problem was that they were so sociable: they were 
street-smart and could get cannabis when they were 13.

'So it's a different group of people who get psychotic as a result of 
cannabis: they were cleverer and more sociable before they got ill.'

People who had suffered a single psychotic episode - such as 
hallucinations or delusions  tended to get better if they gave up 
smoking skunk, with no long-term effects.

But, he said 'sadly a proportion won't recover', adding: 'A third of 
people with cannabis-induced schizophrenia don't stop . . . people 
who persist in smoking cannabis have the worst outcomes. Someone 
who's smoked regularly for five years, they don't recover. It just 
looks like regular schizophrenia.'

Last week's study concluded that 24 per cent of 'first episode 
psychosis' cases in South London were caused by smoking skunk.

South London is a known cannabis hot-spot. But Sir Robin believed 
skunk was now widely available 'across the country', with research 
showing three people now smoked skunk for every individual smoking 
'old-fashioned', weaker hash.

Cannabis use was as big a health problem in the young as smoking 
cigarettes, he said. 'It used to be that people started smoking 
cigarettes and then moved on to cannabis. Now, for increasing 
numbers, it's the other way around.'

The drug had been 'effectively decriminalised, at least in South 
London where I work', he said, as the police 'won't arrest somebody 
simply because they have cannabis for their own use'.

Increasing numbers of teenagers, wanting to stay on the right side of 
the law, are buying 'legal highs' off the internet. These chemicals, 
marketed as 'spice' or 'incense', are designed to mimic the effects 
of cannabis.

But Sir Robin said they could be much more powerful than skunk. Users 
of 'synthetic cannabinoids' are far more likely to end up in A&E than 
those who smoke pot, according to Dr Adam Winstock of the Institute 
of Psychiatry.

'Little 14-year-olds who'd like to experiment, but don't want to do 
anything illegal, buy things off the internet that are legal, but 
also more potent,' said Sir Robin.

'It's sad that some kid may end up taking something worse [than 
cannabis], by getting it in a brownpaper envelope through the post.'
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MAP posted-by: Jay Bergstrom