General fitness, health and nutrition · Public discussion

Cannabis: Minor Chronic Effects

Ian Goddard · 2003-11-07T16:33:13+00:00

Cannabis prohibition is a persistent social tragedy, especially in light of the fact that it is far safer than legal alcohol. Cannabis prohibition is most pernicious in light of its efficacy in treating a range of ailments with a safety profile that exceeds criteria for "safe" applied to legal prescription drugs. http://health.ucsd.edu/news/2003/06_27_Grant.html Minimal Long-Term Effects Of Marijuana Use Found in Central Nervous System by UCSD Researchers An analysis of research studies with long-term, recreational users of marijuana has failed to reveal a substantial, systematic effect on the neurocognitive functioning of users. According to researchers at the University of California, San Diego (UCSD) School of Medicine, the only deleterious side effect found was a minimal malfunction in the domains of learning and forgetting. The findings were particularly significant considering the movement by several states to make cannabis (marijuana) available as a medicinal drug, and questions regarding its potential toxicity over long-term usage. Published in the July issue of the Journal of the International Neuropsychological Society, the study involved a quantitative synthesis of 15 previously published research studies on the non-acute (residual) effects of cannabis on the neurocognitive performance of adult human subjects. The studies included 704 long-term cannabis users and 484 non-users. The neurocognitive performance measurements included simple reaction time, attention, verbal/language, abstraction/executive functioning, perceptual/motor skills, motor skills, learning and forgetting. "Surprisingly, we saw very little evidence of deleterious effects. The only exception was a very small effect in learning new information," said Igor Grant, M.D., the study's senior author, a UCSD professor of psychiatry, and director of the Center for Medicinal Cannabis Research (CMCR), a collaborative, state-supported program between UCSD and UC San Francisco, that oversees 11 studies of the safety and efficacy of medicinal cannabis to treat certain diseases. In describing the negative effects in the study, the research team said the problems observed in learning and forgetting suggest that chronic long-term cannabis use results in selective memory defects. They added that "while the results are compatible with this conclusion, the effected size for both domains was of a very small magnitude." Grant added that the minimal side effects seen "raised the question of practical significance. If we barely find this tiny effect in long-term heavy users of cannabis, then we are unlikely to see deleterious side effects in individuals who receive cannabis for a short time in a medical setting." In addition, Grant said that heavy marijuana users often abuse other drugs, such as alcohol and amphetamines, which also might have long-term neurological effects. This raises the question of the extent to which the other drugs contributed to the minimal problems found in learning and forgetting in the marijuana users. The paper's authors also noted that many of the research studies examined had significant limitations, either with small numbers of subjects or insufficient information about potential confounding factors, such as exposure to other drugs or presence of neuropsychiatric factors such as depression or personality disorders. They noted that only studies that begin with the examination of children and young adolescents before they enter the period of risk to cannabis exposure, can sufficiently reduce the influence of these additional factors. In addition to Grant, the paper's authors included doctoral students Raul Gonzalez, M.S., and Catherine L. Carey, M.S. and Loki Natarajan, Ph.D., UCSD HIV Neurobehavioral Research Center (HNRC) and UCSD Department of Family and Preventive Medicine, and Tanya Wolfson, M.A., UCSD HNRC. The study was supported by the CMRC. ## Study: Pot Doesn't Cause Permanent Brain Damage Fri June 27, 2003 12:18 AM ET By Deena Beasley LOS ANGELES (Reuters) - Smoking marijuana will certainly affect perception, but it does not cause permanent brain damage, researchers from the University of California at San Diego said on Friday in a study. "The findings were kind of a surprise. One might have expected to see more impairment of higher mental function," said Dr. Igor Grant, a UCSD professor of psychiatry and the study's lead author. Other illegal drugs, or even alcohol, can cause brain damage. His team analyzed data from 15 previously published, controlled studies into the impact of long-term, recreational cannabis use on the neurocognitive ability of adults. The studies tested the mental functions of routine pot smokers, but not while they were actually high, Grant said. The results, published in the July issue of the Journal of the International Neuropsychological Society, show that marijuana has only a marginally harmful long-term effect on learning and memory. No effect at all was seen on other functions, including reaction time, attention, language, reasoning ability, and perceptual and motor skills. Grant said the findings are particularly significant amid questions about marijuana's long-term toxicity now that several states are considering whether to make it available as a medicinal drug. In California, growing marijuana for medical purposes is legal under a voter-approved law. The UCSD analysis of studies involving 704 long-term cannabis users and 484 nonusers was sponsored by a state-supported program that oversees research into the use of cannabis to treat certain diseases. Anecdotal evidence has shown that marijuana can help ease pain in patients with diseases like multiple sclerosis or prevent severe nausea in cancer patients, but the effects have yet to be proven in controlled studies, Grant said. The UCSD research team said the problems observed in learning and forgetting suggest that long-term marijuana use results in selective memory defects, but said the impact was of a very small magnitude. "If we barely find this tiny effect in long-term heavy users of cannabis, then we are unlikely to see deleterious side effects in individuals who receive cannabis for a short time in a medical setting," Grant said. In addition, he noted that heavy marijuana users often abuse other drugs, such as alcohol and amphetamines, which also might have long-term neurological effects. Some of the research studies used in the analysis were limited by the numbers of subjects or insufficient information about factors like exposure to other drugs or whether participants suffered from conditions like depression or personality disorders. "If it turned out that new studies find that cannabis is helpful in treating some medical conditions, this enables us to see a marginal level of safety," Grant said. http://www.reuters.com/newsArticle.jhtml;jsessionid=4OYPTFA0MLHGWCRBAEZSFEY?type=scienceNews&story- ID=2998963 http://IanGoddard.net/philo.htm "Our greatest illusion is to believe that we are what we think ourselves to be." Henri Amiel (1821-1881)

Started by Ian Goddard · 7 November 2003 · Last activity 7 November 2003 · 3 posts · 1,084 views

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Original section: General fitness, health and nutrition
Published: 7 November 2003
Last activity: 7 November 2003
Original author: Ian Goddard
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Original post
Ian Goddard
Archived post

7 November 2003, 16:33 UTC #1

Cannabis prohibition is a persistent social tragedy, especially in light of the fact that it is far
safer than legal alcohol. Cannabis prohibition is most pernicious in light of its efficacy in
treating a range of ailments with a safety profile that exceeds criteria for "safe" applied to legal
prescription drugs.
health.ucsd.edu06 27 Grant.html
Minimal Long-Term Effects Of Marijuana Use Found in Central Nervous System by UCSD Researchers
An analysis of research studies with long-term, recreational users of marijuana has failed to reveal
a substantial, systematic effect on the neurocognitive functioning of users. According to
researchers at the University of California, San Diego (UCSD) School of Medicine, the only
deleterious side effect found was a minimal malfunction in the domains of learning and forgetting.
The findings were particularly significant considering the movement by several states to make
cannabis (marijuana) available as a medicinal drug, and questions regarding its potential toxicity
over long-term usage.
Published in the July issue of the Journal of the International Neuropsychological Society, the
study involved a quantitative synthesis of 15 previously published research studies on the non-acute
(residual) effects of cannabis on the neurocognitive performance of adult human subjects.
The studies included 704 long-term cannabis users and 484 non-users. The neurocognitive performance
measurements included simple reaction time, attention, verbal/language, abstraction/executive
functioning, perceptual/motor skills, motor skills, learning and forgetting.
"Surprisingly, we saw very little evidence of deleterious effects. The only exception was a very
small effect in learning new information," said Igor Grant, M.D., the study's senior author, a UCSD
professor of
psychiatry, and director of the Center for Medicinal Cannabis Research
(CMCR), a collaborative, state-supported program between UCSD and UC San Francisco, that oversees 11
studies of the safety and efficacy of medicinal cannabis to treat certain diseases.
In describing the negative effects in the study, the research team said the problems observed in
learning and forgetting suggest that chronic long-term cannabis use results in selective memory
defects. They added that "while the results are compatible with this conclusion, the effected size
for both domains was of a very small magnitude."
Grant added that the minimal side effects seen "raised the question of practical significance. If we
barely find this tiny effect in long-term heavy users of cannabis, then we are unlikely to see
deleterious side effects in individuals who receive cannabis for a short time in a medical setting."
In addition, Grant said that heavy marijuana users often abuse other drugs, such as alcohol and
amphetamines, which also might have long-term neurological effects. This raises the question of the
extent to which the other drugs contributed to the minimal problems found in learning and forgetting
in the marijuana users.
The paper's authors also noted that many of the research studies examined had significant
limitations, either with small numbers of subjects or insufficient information about potential
confounding factors, such as exposure to other drugs or presence of neuropsychiatric factors such as
depression or personality disorders.
They noted that only studies that begin with the examination of children and young adolescents
before they enter the period of risk to cannabis exposure, can sufficiently reduce the influence of
these additional factors.
In addition to Grant, the paper's authors included doctoral students Raul Gonzalez, M.S., and
Catherine L. Carey, M.S. and Loki Natarajan, Ph.D., UCSD HIV Neurobehavioral Research Center (HNRC)
and UCSD Department of Family and Preventive Medicine, and Tanya Wolfson, M.A., UCSD HNRC.
The study was supported by the CMRC.
##
Study: Pot Doesn't Cause Permanent Brain Damage
Fri June 27, 2003 12:18 AM ET
By Deena Beasley
LOS ANGELES (Reuters) - Smoking marijuana will certainly affect perception, but it does not cause
permanent brain damage, researchers from the University of California at San Diego said on Friday
in a study.
"The findings were kind of a surprise. One might have expected to see more impairment of higher
mental function," said Dr. Igor Grant, a UCSD professor of psychiatry and the study's lead author.
Other illegal drugs, or even alcohol, can cause brain damage.
His team analyzed data from 15 previously published, controlled studies into the impact of
long-term, recreational cannabis use on the neurocognitive ability of adults.
The studies tested the mental functions of routine pot smokers, but not while they were actually
high, Grant said.
The results, published in the July issue of the Journal of the International Neuropsychological
Society, show that marijuana has only a marginally harmful long-term effect on learning and memory.
No effect at all was seen on other functions, including reaction time, attention, language,
reasoning ability, and perceptual and motor skills.
Grant said the findings are particularly significant amid questions about marijuana's long-term
toxicity now that several states are considering whether to make it available as a medicinal drug.
In California, growing marijuana for medical purposes is legal under a voter-approved law.
The UCSD analysis of studies involving 704 long-term cannabis users and 484 nonusers was
sponsored by a state-supported program that oversees research into the use of cannabis to treat
certain diseases.
Anecdotal evidence has shown that marijuana can help ease pain in patients with diseases like
multiple sclerosis or prevent severe nausea in cancer patients, but the effects have yet to be
proven in controlled studies, Grant said.
The UCSD research team said the problems observed in learning and forgetting suggest that long-term
marijuana use results in selective memory defects, but said the impact was of a very small
magnitude.
"If we barely find this tiny effect in long-term heavy users of cannabis, then we are unlikely to
see deleterious side effects in individuals who receive cannabis for a short time in a medical
setting," Grant said.
In addition, he noted that heavy marijuana users often abuse other drugs, such as alcohol and
amphetamines, which also might have long-term neurological effects.
Some of the research studies used in the analysis were limited by the numbers of subjects or
insufficient information about factors like exposure to other drugs or whether participants suffered
from conditions like depression or personality disorders.
"If it turned out that new studies find that cannabis is helpful in treating some medical
conditions, this enables us to see a marginal level of safety," Grant said.
reuters.comnewsArticle.jhtml;jsessionid=4OYPTFA0MLHGWCRBAEZSFEY
ID=2998963
iangoddard.netphilo.htm
"Our greatest illusion is to believe that we are what
we think ourselves to be." Henri Amiel (1821-1881)

Report
John H.
Archived post

7 November 2003, 16:33 UTC #2

Damn right Ian, many studies now point to powerful benefits for cannabinoids. Unfortunately when
cannabis is mentioned people only think of THC and particuarly in the USA the political climate is
absurd. Eg. Some months ago the DEA issued a notice to pet shop owners to remove all birdseed
products with pot seed in it ... . By the way, good evidence that dicannabidol(spelling!) should be
extensively trialled for stroke and head trauma victims. Its ability to save neurons is remarkable,
has anti-inflammatory properties, in vitro toxicity is impossible (or at least have never been
demonstrated). There is also good evidence to for cannabinoid antitumoural properties (breast,
glioma, prostrate) but won't hear that in the news ... .
By way of contrast, look at the studies on alcohol.
Ian, thanks for these posts, you usually throw up some interesting stuff.
John H.
--
[email hidden]
remove YYY in reply "Ian Goddard" <[email hidden]> wrote in message
"]news:[email hidden]...
Quoted message said:

Cannabis prohibition is a persistent social tragedy, especially in light of the fact that it is
far safer than legal alcohol. Cannabis prohibition is most pernicious in light of its efficacy in
treating a range of ailments with a safety profile that exceeds criteria for "safe" applied to
legal prescription drugs.
health.ucsd.edu06 27 Grant.html
Minimal Long-Term Effects Of Marijuana Use Found in Central Nervous System by UCSD Researchers
An analysis of research studies with long-term, recreational users of marijuana has failed to
reveal a substantial, systematic effect on the neurocognitive functioning of users. According to
researchers at the University of California, San Diego (UCSD) School of Medicine, the only
deleterious side effect found was a minimal malfunction in the domains of learning and forgetting.
The findings were particularly significant considering the movement by several states to make
cannabis (marijuana) available as a medicinal drug, and questions regarding its potential toxicity
over long-term usage.
Published in the July issue of the Journal of the International Neuropsychological Society, the
study involved a quantitative synthesis of 15 previously published research studies on the
non-acute (residual) effects of cannabis on the neurocognitive performance of adult human
subjects.
The studies included 704 long-term cannabis users and 484 non-users. The neurocognitive
performance measurements included simple reaction time, attention, verbal/language,
abstraction/executive functioning, perceptual/motor skills, motor skills, learning and forgetting.
"Surprisingly, we saw very little evidence of deleterious effects. The only exception was a very
small effect in learning new information," said Igor Grant, M.D., the study's senior author, a
UCSD professor of
psychiatry, and director of the Center for Medicinal Cannabis Research
(CMCR), a collaborative, state-supported program between UCSD and UC San Francisco, that oversees
11 studies of the safety and efficacy of medicinal cannabis to treat certain diseases.
In describing the negative effects in the study, the research team said the problems observed in
learning and forgetting suggest that chronic long-term cannabis use results in selective memory
defects. They added that "while the results are compatible with this conclusion, the effected size
for both domains was of a very small magnitude."
Grant added that the minimal side effects seen "raised the question of practical significance. If
we barely find this tiny effect in long-term heavy users of cannabis, then we are unlikely to see
deleterious side effects in individuals who receive cannabis for a short time in a medical
setting."
In addition, Grant said that heavy marijuana users often abuse other drugs, such as alcohol and
amphetamines, which also might have long-term neurological effects. This raises the question of
the extent to which the other drugs contributed to the minimal problems found in learning and
forgetting in the marijuana users.
The paper's authors also noted that many of the research studies examined had significant
limitations, either with small numbers of subjects or insufficient information about potential
confounding factors, such as exposure to other drugs or presence of neuropsychiatric factors such
as depression or personality disorders.
They noted that only studies that begin with the examination of children and young adolescents
before they enter the period of risk to cannabis exposure, can sufficiently reduce the influence
of these additional factors.
In addition to Grant, the paper's authors included doctoral students Raul Gonzalez, M.S., and
Catherine L. Carey, M.S. and Loki Natarajan, Ph.D., UCSD HIV Neurobehavioral Research Center
(HNRC) and UCSD Department of Family and Preventive Medicine, and Tanya Wolfson, M.A., UCSD HNRC.
The study was supported by the CMRC.
##
Study: Pot Doesn't Cause Permanent Brain Damage
Fri June 27, 2003 12:18 AM ET
By Deena Beasley
LOS ANGELES (Reuters) - Smoking marijuana will certainly affect perception, but it does not cause
permanent brain damage, researchers from the University of California at San Diego said on Friday
in a study.
"The findings were kind of a surprise. One might have expected to see more impairment of higher
mental function," said Dr. Igor Grant, a UCSD professor of psychiatry and the study's lead author.
Other illegal drugs, or even alcohol, can cause brain damage.
His team analyzed data from 15 previously published, controlled studies into the impact of
long-term, recreational cannabis use on the neurocognitive ability of adults.
The studies tested the mental functions of routine pot smokers, but not while they were actually
high, Grant said.
The results, published in the July issue of the Journal of the International
Neuropsychological Society, show that marijuana has only a marginally harmful long-term effect
on learning and memory.
No effect at all was seen on other functions, including reaction time, attention, language,
reasoning ability, and perceptual and motor skills.
Grant said the findings are particularly significant amid questions about marijuana's long-term
toxicity now that several states are considering whether to make it available as a medicinal drug.
In California, growing marijuana for medical purposes is legal under a voter-approved law.
The UCSD analysis of studies involving 704 long-term cannabis users and 484 nonusers was sponsored
by a state-supported program that oversees research into the use of cannabis to treat certain
diseases.
Anecdotal evidence has shown that marijuana can help ease pain in patients with diseases like
multiple sclerosis or prevent severe nausea in cancer patients, but the effects have yet to be
proven in controlled studies, Grant said.
The UCSD research team said the problems observed in learning and forgetting suggest that
long-term marijuana use results in selective memory defects, but said the impact was of a very
small magnitude.
"If we barely find this tiny effect in long-term heavy users of cannabis, then we are unlikely to
see deleterious side effects in individuals who receive cannabis for a short time in a medical
setting," Grant said.
In addition, he noted that heavy marijuana users often abuse other drugs, such as alcohol and
amphetamines, which also might have long-term neurological effects.
Some of the research studies used in the analysis were limited by the numbers of subjects or
insufficient information about factors like exposure to other drugs or whether participants
suffered from conditions like depression or personality disorders.
"If it turned out that new studies find that cannabis is helpful in treating some medical
conditions, this enables us to see a marginal level of safety," Grant said.

reuters.comnewsArticle.jhtml;jsessionid=4OYPTFA0MLHGWCRBAEZSFEY
type=scienceNews&storyID=2998963
Quoted message said:
iangoddard.netphilo.htm
"Our greatest illusion is to believe that we are what
we think ourselves to be." Henri Amiel (1821-1881)

Report
Ian Goddard
Archived post

7 November 2003, 16:34 UTC #3

health.ucsd.edu06 27 Grant.html
John H. said:

Damn right Ian, many studies now point to powerful benefits for cannabinoids. Unfortunately when
cannabis is mentioned people only think of THC and particuarly in the USA the political climate is
absurd. Eg. Some months ago the DEA issued a notice to pet shop owners to remove all birdseed
products with pot seed in it ... . By the way, good evidence that dicannabidol(spelling!) should be
extensively trialled for stroke and head trauma victims. Its ability to save neurons is remarkable,
has anti-inflammatory properties, in vitro toxicity is impossible (or at least have never been
demonstrated). There is also good evidence to for cannabinoid antitumoural properties (breast,
glioma, prostrate) but won't hear that in the news ... .
IAN: Here are a couple cannabidiol abstracts along with a review of the pharmacology of
cannabinoids that concludes: "Properties of cannabis that might be of therapeutic use include
analgesia, muscle relaxation, immunosuppression, sedation, improvement of mood, stimulation of
appetite, antiemesis, lowering of intraocular pressure, bronchodilation, neuroprotection and
induction of apoptosis in cancer cells." Here's more:
J Clin Pharmacol. 2002 Nov;42(11 Suppl):11S-19S.
Cannabidiol: an overview of some pharmacological aspects.
Mechoulam R, Parker LA, Gallily R.
Department of Medicinal Chemistry and Natural Products, Hebrew University of Jerusalem, Israel.
Over the past few years, considerable attention has focused on cannabidiol (CBD), a major
nonpsychotropic constituent of cannabis. The authors present a review on the chemistry of CBD and
discuss the anticonvulsive, antianxiety, antipsychotic, antinausea, and antirheumatoid arthritic
properties of CBD. CBD does not bind to the known cannabinoid receptors, and its mechanism of action
is yet unknown. It is possible that, in part at least, its effects are due to its recently
discovered inhibition of anandamide uptake and hydrolysis and to its antioxidative effect.
ncbi.nlm.nih.govquery.fcgi
t=Abstract
*****************************************************
J Clin Pharmacol. 1981 Aug-Sep;21(8-9 Suppl):417S-427S.
Hypnotic and antiepileptic effects of cannabidiol.
Carlini EA, Cunha JM.
Clinical trials with cannabidiol (CBD) in healthy volunteers, isomniacs, and epileptic patients
conducted in the authors' laboratory from 1972 up to the present are reviewed. Acute doses of
cannabidiol ranging from 10 to 600 mg and chronic administration of 10 mg for 20 days or 3 mg/kg/day
for 30 days did not induce psychologic or physical symptoms suggestive of psychotropic or toxic
effects; however, several volunteers complained of somnolence. Complementary laboratory tests (EKG,
blood pressure, and blood and urine analysis) revealed no sign of toxicity. Doses of 40, 80, and 160
mg cannabidiol were compared to placebo and 5 mg nitrazepam in 15 insomniac volunteers. Subjects
receiving 160 mg cannabidiol reported having slept significantly more than those receiving placebo;
the volunteers also reported significantly less dream recall; with the three doses of cannabidiol
than with placebo. Fifteen patients suffering from secondary generalized epilepsy refractory to
known antiepileptic drugs received either 200 to 300 mg cannabidiol daily or placebo for as long as
4.5 months. Seven out of the eight epileptics receiving cannabidiol had improvement of their disease
state, whereas only one placebo patient improved.
ncbi.nlm.nih.govquery.fcgi
*****************************************************
Clin Pharmacokinet. 2003;42(4):327-60.
Pharmacokinetics and pharmacodynamics of cannabinoids.
Grotenhermen F.
Nova-Institut, Hurth, Germany. [email hidden]
Delta(9)-Tetrahydrocannabinol (THC) is the main source of the pharmacological effects caused by the
consumption of cannabis, both the marijuana-like action and the medicinal benefits of the plant.
However, its acid metabolite THC-COOH, the non-psychotropic cannabidiol (CBD), several cannabinoid
analogues and newly discovered modulators of the endogenous cannabinoid system are also promising
candidates for clinical research and therapeutic uses. Cannabinoids exert many effects through
activation of G-protein-coupled cannabinoid receptors in the brain and peripheral tissues.
Additionally, there is evidence for non-receptor-dependent mechanisms. Natural cannabis products and
single cannabinoids are usually inhaled or taken orally; the rectal route, sublingual
administration, transdermal delivery, eye drops and aerosols have only been used in a few studies
and are of little relevance in practice today. The pharmacokinetics of THC vary as a function of its
route of administration. Pulmonary assimilation of inhaled THC causes a maximum plasma concentration
within minutes,
psychotropic effects start within seconds to a few minutes, reach a maximum after 15-30 minutes,
and taper off within 2-3 hours. Following oral ingestion, psychotropic effects set in with a
delay of 30-90 minutes, reach their maximum after 2-3 hours and last for about 4-12 hours,
depending on dose and specific effect. At doses exceeding the
ppsychotropic threshold, ingestion of cannabis usually causes enhanced well-being and relaxation
with an intensification of ordinary sensory experiences. The most important acute adverse effects
caused by overdosing are anxiety and panic attacks, and with regard to somatic effects increased
heart rate and changes in blood pressure. Regular use of cannabis may lead to dependency and to a
mild withdrawal syndrome. The existence and the intensity of possible long-term adverse effects
on psyche and cognition, immune system, fertility and pregnancy remain controversial. They are
reported to be low in humans and do not preclude legitimate therapeutic use of cannabis-based
drugs. Properties of cannabis that might be of therapeutic use include analgesia, muscle
relaxation, immunosuppression, sedation, improvement of mood, stimulation of appetite,
antiemesis, lowering of intraocular pressure, bronchodilation, neuroprotection and induction of
apoptosis in cancer cells.
ncbi.nlm.nih.govquery.fcgi
t=Abstract
iangoddard.netjournal.htm
"To lengthen thy life, lessen thy meals." Ben Franklin
Ongoing CR monkey study update: "In the monkeys...those on reduced feeding since the study started
are dying at a rate that is about half that of the monkeys receiving a full food ration."
Associated Press: Eating less may extend human life. August 1, 2002 :
msnbc.com788746.asp

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