couch-potato
07-27-2007, 06:22 AM
Link! (http://www.newscientist.com/article.ns?id=dn12363&feedId=online-news_rss20)
Cannabis use increases risk of psychotic illness
01:16 27 July 2007
NewScientist.com news service
New Scientist and Reuters
Using marijuana increases the risk of one day developing a psychotic illness such as schizophrenia, according to a study that provides some of the strongest evidence yet linking the drug to a mental disorder.
Marijuana is one the most commonly used illegal substances in many countries, with up to 20% of young people in places such as Britain reporting either some use or heavy use, British researchers said, citing government statistics.
Many consider it on par with alcohol or tobacco but the results shows marijuana poses a danger many smokers underestimate, said team member Stanley Zammit, a psychiatrist at Cardiff University and the University of Bristol in the UK.
The researchers found that marijuana users had a 41% increased chance of developing psychosis marked by symptoms of hallucinations or delusions later in life than those who never used the drug. The risk rose with heavier consumption.
"If you compare other substances like alcohol or tobacco, it may not be as harmful, but what we are saying is neither is it completely safe," Zammit said.
Other findings have highlighted the link between marijuana use and the risk of schizophrenia-like symptoms such as paranoia, hearing voices and seeing things that are not there.
But this study marks one of the most comprehensive, thorough and reliable reviews of its kind and should serve as a warning, two Danish researchers wrote in an accompanying article.
Raise warning
They said the results mean an estimated 800 cases of schizophrenia in the UK could be prevented each year by ending marijuana consumption.
"We therefore agree with the authors' conclusion that there is now sufficient evidence to warn young people that cannabis use will increase their risk of psychosis later in life," they wrote.
The team did not look directly at people who used marijuana but instead reviewed 35 studies in search of a potential connection between psychotic illness and using marijuana.
They reviewed evidence from studies ranging from one year to 27 years and only looked at research that did not include people already showing signs of psychotic illness.
The researchers also adjusted for factors â?? such as depression or a susceptibility to harder drugs â?? that could one day lead to a mental disorder to focus more directly on the links between marijuana and psychosis, Zammit said.
"We have described a consistent association between cannabis use and psychotic symptoms, including disabling psychotic disorders," the team wrote.
But both Zammit and the Danish researchers said ultimate proof to show a direct relationship would be have to come through a randomised trial of healthy young people and long-term follow-up.
Such a study, however, is unlikely given marijuana is illegal in most countries and the ethical questions given the drug's known harmful effects, they said.
Cannabis use increases risk of psychotic illness
01:16 27 July 2007
NewScientist.com news service
New Scientist and Reuters
Using marijuana increases the risk of one day developing a psychotic illness such as schizophrenia, according to a study that provides some of the strongest evidence yet linking the drug to a mental disorder.
Marijuana is one the most commonly used illegal substances in many countries, with up to 20% of young people in places such as Britain reporting either some use or heavy use, British researchers said, citing government statistics.
Many consider it on par with alcohol or tobacco but the results shows marijuana poses a danger many smokers underestimate, said team member Stanley Zammit, a psychiatrist at Cardiff University and the University of Bristol in the UK.
The researchers found that marijuana users had a 41% increased chance of developing psychosis marked by symptoms of hallucinations or delusions later in life than those who never used the drug. The risk rose with heavier consumption.
"If you compare other substances like alcohol or tobacco, it may not be as harmful, but what we are saying is neither is it completely safe," Zammit said.
Other findings have highlighted the link between marijuana use and the risk of schizophrenia-like symptoms such as paranoia, hearing voices and seeing things that are not there.
But this study marks one of the most comprehensive, thorough and reliable reviews of its kind and should serve as a warning, two Danish researchers wrote in an accompanying article.
Raise warning
They said the results mean an estimated 800 cases of schizophrenia in the UK could be prevented each year by ending marijuana consumption.
"We therefore agree with the authors' conclusion that there is now sufficient evidence to warn young people that cannabis use will increase their risk of psychosis later in life," they wrote.
The team did not look directly at people who used marijuana but instead reviewed 35 studies in search of a potential connection between psychotic illness and using marijuana.
They reviewed evidence from studies ranging from one year to 27 years and only looked at research that did not include people already showing signs of psychotic illness.
The researchers also adjusted for factors â?? such as depression or a susceptibility to harder drugs â?? that could one day lead to a mental disorder to focus more directly on the links between marijuana and psychosis, Zammit said.
"We have described a consistent association between cannabis use and psychotic symptoms, including disabling psychotic disorders," the team wrote.
But both Zammit and the Danish researchers said ultimate proof to show a direct relationship would be have to come through a randomised trial of healthy young people and long-term follow-up.
Such a study, however, is unlikely given marijuana is illegal in most countries and the ethical questions given the drug's known harmful effects, they said.