Regular cannabis users 'at greater risk of mental illness'
July 2, 2003
Reference: Mass R. et al, Psychopathyology 2001:34-209-214, Cannabis Use, Schizotypal Traits, and Cognitive Function in Healthy Subjects.
Marijuana use can stimulate the symptoms of schizophrenia, according to researchers at Okayama University in Japan. Their study found similarities between the brain dysfunctions in schizophrenic patients and the disruptions in brain activity caused by marijuana use.
Marijuana Linked to Schizophrenia, Depression
By Adam Marcus
THURSDAY, Nov. 21 2002 (HealthScoutNews)
As many as one in seven cases of schizophrenia could be prevented by eradicating marijuana. That's the contention of a new study of Swedish soldiers that found smoking pot increases the risk of the psychiatric disorder by about 30 percent. The Swedish study is one of three reports in this week's British Medical Journal linking marijuana to emotional problems, including depression and anxiety, as well as schizophrenia.
Schizophrenia Society of Sask. Warns Doctors of Marijuana Risk
Doctors should be wary when asked to prescribe medical marijuana, says the Schizophrenia Society of Saskatchewan.
"Marijuana is detrimental to someone who has schizophrenia. It's a bad mix," said Kathleen Thompson, executive director of the Schizophrenia Society of Saskatchewan.
The society has written the College of Physicians and Surgeons of Saskatchewan urging doctors to be sure their patients do not have a history of schizophrenia prior to prescribing medical marijuana.
"Members of our society reported that their ill relatives have been hinting at their interest to seek out medical specialists in an effort to have marijuana prescribed for their chronic pain," wrote Grant Rathwell, then-president of the society.
"Since many of these consumers can be very persuasive and manipulative, we felt that we should make you and your members aware in the event that some of these persons whose medical history is unknown to your members come shopping around for such prescriptions."
Thompson says many people with schizophrenia are addicted to drugs or alcohol as a way to cope with their illness.
Finding a doctor to prescribe marijuana would justify their smoking it and they would have one less thing to worry about because they couldn't be charged with possessing the drug.
But their addictions come with a price, Thompson says.
"If they smoke marijuana regularly, chronically, it's much more challenging for them to manage the illness."
As well, the illness can be triggered if someone who is unaware they have a genetic predisposition for schizophrenia smokes marijuana, she says.
The College of Physicians and Surgeons of Saskatchewan included an excerpt from the society's letter in one of its newsletters sent to doctors throughout the province.
Dr. Karen Shaw, deputy registrar of the college, calls the issue of medical marijuana "a hot potato." She says people with schizophrenia aren't the only ones who may be looking for a prescription for marijuana.
"There is a population out there that is going to find something to try and get access to medical marijuana which will decrease the problem they have accessing it and the risk of a criminal record," she said.
Shaw says the federal government guidelines for prescribing medical marijuana include palliative care patients expected to die within 12 months, people with illnesses such as multiple sclerosis, those who suffer from seizures and people who experience chronic pain.
"Sometimes it's not easy to diagnose chronic pain conditions," she said.
The college expects doctors to use medical marijuana as a last resort after all other options have been tried and found to be ineffective.
Shaw says the lack of research and medical trials of medical marijuana is troubling, and doctors don't fully understand what the long-term implications are of taking medical marijuana.
Source: StarPhoenix, The (CN SN)
Author: Lana Haight, The StarPhoenix
Published: Saturday, May 22, 2004
Copyright: 2004 The StarPhoenix
Cannabis Link To Schizophrenia Rise - http://cannabisnews.com/news/thread15887.shtml
Marijuana Linked to Schizophrenia, Depression - http://cannabisnews.com/news/thread14808.shtml
Pot May Cause Depression, Schizophrenia - http://cannabisnews.com/news/thread14804.shtml
Study finds cannabis triggers transient schizophrenia-like symptoms
New Haven, Conn. -- The principal active ingredient in marijuana causes transient schizophrenia-like symptoms ranging from suspiciousness and delusions to impairments in memory and attention, according to a Yale research study. Lead author D. Cyril D'Souza, M.D., associate professor of psychiatry at Yale School of Medicine, said the study was an attempt to clarify a long known association between cannabis and psychosis in the hopes of finding another clue about the pathophysiology of schizophrenia.
"Just as studies with amphetamines and ketamine advanced the notion that brain systems utilizing the chemical messengers dopamine and NMDA receptors may be involved in the pathophysiology in schizophrenia, this study provides some tantalizing support for the hypotheses that the brain receptor system that cannabis acts on may be involved in the pathophysiology of schizophrenia," he said. "Clearly, further work is needed to test this hypothesis."
D'Souza and his co-researchers administered various doses of delta-9-THC, the main active ingredient in cannabis, to subjects who were screened for any vulnerability to schizophrenia. Some subjects developed symptoms resembling those of schizophrenia that lasted approximately one half hour to one hour. These symptoms included suspiciousness, unusual thoughts, paranoia, thought disorder, blunted affect, reduced spontaneity, reduced interaction with the interviewer, and problems with memory and attention. THC also induced euphoria and increased levels of the stress hormone cortisol. There were no side effects in the study participants one, three and six months after the study.
The findings of this study go along with several other lines of evidence that suggest a contribution of cannabis and/or abnormalities in the brain cannabinoid receptor system to the pathophysiology of schizophrenia.
Co-authors included Edward Perry, M.D., Lisa MacDougal, Yola Ammerman, Yu-Te Wu, Gabriel Braley, Ralitza Gueorguieva, and John Krystal, M.D., of Yale, and Thomas Cooper of Columbia College of Physicians and Surgeons.
Citation: Neuropsychopharmacology, Advanced Online Publication (June 2, 2004)
Public release date: 14-Jun-2004
Contact: Jacqueline Weaver