seven times more likely to suffer from psychosis
Ultra-potent skunk cannabis is seven times more likely to trigger psychotic illnesses such as schizophrenia than traditional hash, a study has warned.
The research, by the highly-respected Institute of Psychiatry in London, will deepen concerns over the safety of cannabis amid political controversy over its criminal status.
Dr Marta Di Forti, who led the research, said: 'Our study is the first to demonstrate the risk of psychosis is much greater among frequent cannabis users, especially among those using skunk, rather than among occasional users of traditional hash.
At risk: People who habitually use skunk could suffer from psychosis
'Psychosis was associated with more frequent and longer use of cannabis. Our most striking finding is that patients with a first episode of psychosis preferentially used high-potency cannabis preparations of the skunk variety.'
Skunk contains high levels of the psychoactive ingredient delta-9 tetrahydrocannabinol, known as THC, which can trigger psychotic symptoms.
In South-East London, where the study was carried out, the THC content of hash is less than 4 per cent but in skunk it is 18 per cent.
In the past two years skunk has come to dominate the cannabis market, with its price dropping to under ?5 a gram.
Some experts believe skunk is so potent it should be treated differently from other types of cannabis and put on a par with Class A drugs such as cocaine and Ecstasy.
Last month Professor David Nutt was forced to step down as chairman of the Government's Advisory Council on the Misuse of Drugs after criticising the decision to push cannabis back into the more serious Class B after a period of downgrading.
Its downgrading from B to C had been increasingly controversial as concern grew over its effects.
The sacking of Professor Nutt, who claimed the drug was less harmful than alcohol and tobacco, caused a revolt among members of the advisory council with several resigning.
The number of under-25s smoking cannabis was almost one in five last year, even though use has been falling since 2001.
This latest study, published in the British Journal of Psychiatry, involved 280 patients aged 18 to 65 attending a South London hospital with a first episode of psychosis, compared with 174 healthy people.
Those with psychosis were twice as likely to have used cannabis for longer than five years, and more than six times likely to take it every day.
Growing problem: A cannabis factory dicovered by Police in Malham Road, Forest Hill, Lewisham
Significantly cannabis users who smoked skunk were 6.8 times more at risk of being treated for a psychosis than those who took hash.
Other studies show hash users are at double the risk of suffering psychosis compared with those who never use the drug.
Marjorie Wallace, chief executive of the mental health charity SANE, said: 'Those of us on the front line, including psychiatrists, police and families, know that skunk cannabis can be particularly dangerous for the significant minority of people vulnerable to mental illness.
'We need to give out an uncompromising warning about the specific links between skunk and mental illness.'
Drug charity Turning Point welcomed the findings. Spokesman Harry Walker said: 'We now have confirmation of what many suspected and it is important that we act on these findings.'
Ultra-potent skunk cannabis is seven times more likely to trigger psychotic illnesses such as schizophrenia than traditional hash, a study has warned.
The research, by the highly-respected Institute of Psychiatry in London, will deepen concerns over the safety of cannabis amid political controversy over its criminal status.
Dr Marta Di Forti, who led the research, said: 'Our study is the first to demonstrate the risk of psychosis is much greater among frequent cannabis users, especially among those using skunk, rather than among occasional users of traditional hash.
At risk: People who habitually use skunk could suffer from psychosis'Psychosis was associated with more frequent and longer use of cannabis. Our most striking finding is that patients with a first episode of psychosis preferentially used high-potency cannabis preparations of the skunk variety.'
Skunk contains high levels of the psychoactive ingredient delta-9 tetrahydrocannabinol, known as THC, which can trigger psychotic symptoms.
In South-East London, where the study was carried out, the THC content of hash is less than 4 per cent but in skunk it is 18 per cent.
In the past two years skunk has come to dominate the cannabis market, with its price dropping to under ?5 a gram.
Some experts believe skunk is so potent it should be treated differently from other types of cannabis and put on a par with Class A drugs such as cocaine and Ecstasy.
Last month Professor David Nutt was forced to step down as chairman of the Government's Advisory Council on the Misuse of Drugs after criticising the decision to push cannabis back into the more serious Class B after a period of downgrading.
Its downgrading from B to C had been increasingly controversial as concern grew over its effects.
The sacking of Professor Nutt, who claimed the drug was less harmful than alcohol and tobacco, caused a revolt among members of the advisory council with several resigning.
The number of under-25s smoking cannabis was almost one in five last year, even though use has been falling since 2001.
This latest study, published in the British Journal of Psychiatry, involved 280 patients aged 18 to 65 attending a South London hospital with a first episode of psychosis, compared with 174 healthy people.
Those with psychosis were twice as likely to have used cannabis for longer than five years, and more than six times likely to take it every day.
Growing problem: A cannabis factory dicovered by Police in Malham Road, Forest Hill, LewishamSignificantly cannabis users who smoked skunk were 6.8 times more at risk of being treated for a psychosis than those who took hash.
Other studies show hash users are at double the risk of suffering psychosis compared with those who never use the drug.
Marjorie Wallace, chief executive of the mental health charity SANE, said: 'Those of us on the front line, including psychiatrists, police and families, know that skunk cannabis can be particularly dangerous for the significant minority of people vulnerable to mental illness.
'We need to give out an uncompromising warning about the specific links between skunk and mental illness.'
Drug charity Turning Point welcomed the findings. Spokesman Harry Walker said: 'We now have confirmation of what many suspected and it is important that we act on these findings.'
, no pun intended
Comment