Marijuana Links ~ Science Daily News, etc.
Marijuana use dampens brain's response to reward over time, study finds
Changes may increase risk of continued drug use and addiction
University of Michigan Health System / July 6, 2016
https://www.sciencedaily.com/releases/2016/07/160706114407.htm
Most people would get a little 'rush' out of the idea that they're about to win some money. In fact, if you could look into their brain at that very moment, you'd see lots of activity in the part of the brain that responds to rewards.
But for people who've been using marijuana, that rush just isn't as big -- and gets smaller over time, a new study finds.
And that dampened, blunted response may actually open marijuana users up to more risk of becoming addicted to that drug or others.
The new results come from the first long-term study of young marijuana users that tracked brain responses to rewards over time. It was performed at the University of Michigan Medical School.
Published in JAMA Psychiatry, it shows measurable changes in the brain's reward system with marijuana use -- even when other factors like alcohol use and cigarette smoking were taken into account.
"What we saw was that over time, marijuana use was associated with a lower response to a monetary reward," says senior author and U-M neuroscientist Mary Heitzeg, Ph.D. "This means that something that would be rewarding to most people was no longer rewarding to them, suggesting but not proving that their reward system has been 'hijacked' by the drug, and that they need the drug to feel reward -- or that their emotional response has been dampened."
Watching the reward centers
The study involved 108 people in their early 20s -- the prime age for marijuana use. All were taking part in a larger study of substance use, and all had brain scans at three points over four years. Three-quarters were men, and nearly all were white.
While their brain was being scanned in a functional MRI scanner, they played a game that asked them to click a button when they saw a target on a screen in front of them. Before each round, they were told they might win 20 cents, or $5 -- or that they might lose that amount, have no reward or loss.
The researchers were most interested at what happened in the reward centers of the volunteers' brains -- the area called the nucleus accumbens. And the moment they cared most about was that moment of anticipation, when the volunteers knew they might win some money, and were anticipating performing the simple task that it would take to win.
In that moment of anticipating a reward, the cells of the nucleus accumbens usually swing into action, pumping out a 'pleasure chemical' called dopamine. The bigger the response, the more pleasure or thrill a person feels -- and the more likely they'll be to repeat the behavior later.
But the more marijuana use a volunteer reported, the smaller the response in their nucleus accumbens over time, the researchers found.
While the researchers didn't also look at the volunteers' responses to marijuana-related cues, other research has shown that the brains of people who use a high-inducing drug repeatedly often respond more strongly when they're shown cues related to that drug. The increased response means the drug has become associated in their brains with positive, rewarding feelings. And that can make it harder to stop seeking out the drug and using it.
If this is true with marijuana users, says first author Meghan Martz, doctoral student in developmental psychology at U-M, "It may be that the brain can drive marijuana use, and that the use of marijuana can also affect the brain. We're still unable to disentangle the cause and effect in the brain's reward system, but studies like this can help that understanding."
Change over time
Regardless, the new findings show that there is change in the reward system over time with marijuana use. Heitzeg and her colleagues also showed recently in a paper in Developmental Cognitive Neuroscience that marijuana use impacts emotional functioning.
The new data on response to potentially winning money may also be further evidence that long-term marijuana use dampens a person's emotional response -- something scientists call anhedonia.
"We are all born with an innate drive to engage in behaviors that feel rewarding and give us pleasure," says co-author Elisa Trucco, Ph.D., psychologist at the Center for Children and Families at Florida International University. "We now have convincing evidence that regular marijuana use impacts the brain's natural response to these rewards. In the long run, this is likely to put these individuals at risk for addiction."
Marijuana's reputation as a "safe" drug, and one that an increasing number of states are legalizing for small-scale recreational use, means that many young people are trying it -- as many as a third of college-age people report using it in the past year.
But Heitzeg says that her team's findings, and work by other addiction researchers, has shown that it can cause effects including problems with emotional functioning, academic problems, and even structural brain changes. And, the earlier in life someone tries marijuana, the faster their transition to becoming dependent on the drug, or other substances.
"Some people may believe that marijuana is not addictive or that it's 'better' than other drugs that can cause dependence," says Heitzeg, who is an assistant professor of psychiatry at the U-M Medical School and member of the U-M Addiction Research Center. "But this study provides evidence that it's affecting the brain in a way that may make it more difficult to stop using it. It changes your brain in a way that may change your behavior, and where you get your sense of reward from."
She is among the neuroscientists and psychologists leading a nationwide study called ABCD, for Adolescent Brain Cognitive Development. That study will track thousands of today's pre-teens nationwide over 10 years, looking at many aspects of their health and functioning, including brain development via brain scans. Since some of the teens in the study are likely to use marijuana, the study will provide a better chance of seeing what happens over time.
Story Source:
The above post is reprinted from materials provided by University of Michigan Health System. Note: Content may be edited for style and length.
Journal Reference:
http://www.uofmhealth.org/news/archive/201607/marijuana-use-dampens-brains-response-reward-over-time-u-m
Changes may increase risk of continued drug use and addiction
University of Michigan Health System / July 6, 2016
https://www.sciencedaily.com/releases/2016/07/160706114407.htm
Most people would get a little 'rush' out of the idea that they're about to win some money. In fact, if you could look into their brain at that very moment, you'd see lots of activity in the part of the brain that responds to rewards.
But for people who've been using marijuana, that rush just isn't as big -- and gets smaller over time, a new study finds.
And that dampened, blunted response may actually open marijuana users up to more risk of becoming addicted to that drug or others.
The new results come from the first long-term study of young marijuana users that tracked brain responses to rewards over time. It was performed at the University of Michigan Medical School.
Published in JAMA Psychiatry, it shows measurable changes in the brain's reward system with marijuana use -- even when other factors like alcohol use and cigarette smoking were taken into account.
"What we saw was that over time, marijuana use was associated with a lower response to a monetary reward," says senior author and U-M neuroscientist Mary Heitzeg, Ph.D. "This means that something that would be rewarding to most people was no longer rewarding to them, suggesting but not proving that their reward system has been 'hijacked' by the drug, and that they need the drug to feel reward -- or that their emotional response has been dampened."
Watching the reward centers
The study involved 108 people in their early 20s -- the prime age for marijuana use. All were taking part in a larger study of substance use, and all had brain scans at three points over four years. Three-quarters were men, and nearly all were white.
While their brain was being scanned in a functional MRI scanner, they played a game that asked them to click a button when they saw a target on a screen in front of them. Before each round, they were told they might win 20 cents, or $5 -- or that they might lose that amount, have no reward or loss.
The researchers were most interested at what happened in the reward centers of the volunteers' brains -- the area called the nucleus accumbens. And the moment they cared most about was that moment of anticipation, when the volunteers knew they might win some money, and were anticipating performing the simple task that it would take to win.
In that moment of anticipating a reward, the cells of the nucleus accumbens usually swing into action, pumping out a 'pleasure chemical' called dopamine. The bigger the response, the more pleasure or thrill a person feels -- and the more likely they'll be to repeat the behavior later.
But the more marijuana use a volunteer reported, the smaller the response in their nucleus accumbens over time, the researchers found.
While the researchers didn't also look at the volunteers' responses to marijuana-related cues, other research has shown that the brains of people who use a high-inducing drug repeatedly often respond more strongly when they're shown cues related to that drug. The increased response means the drug has become associated in their brains with positive, rewarding feelings. And that can make it harder to stop seeking out the drug and using it.
If this is true with marijuana users, says first author Meghan Martz, doctoral student in developmental psychology at U-M, "It may be that the brain can drive marijuana use, and that the use of marijuana can also affect the brain. We're still unable to disentangle the cause and effect in the brain's reward system, but studies like this can help that understanding."
Change over time
Regardless, the new findings show that there is change in the reward system over time with marijuana use. Heitzeg and her colleagues also showed recently in a paper in Developmental Cognitive Neuroscience that marijuana use impacts emotional functioning.
The new data on response to potentially winning money may also be further evidence that long-term marijuana use dampens a person's emotional response -- something scientists call anhedonia.
"We are all born with an innate drive to engage in behaviors that feel rewarding and give us pleasure," says co-author Elisa Trucco, Ph.D., psychologist at the Center for Children and Families at Florida International University. "We now have convincing evidence that regular marijuana use impacts the brain's natural response to these rewards. In the long run, this is likely to put these individuals at risk for addiction."
Marijuana's reputation as a "safe" drug, and one that an increasing number of states are legalizing for small-scale recreational use, means that many young people are trying it -- as many as a third of college-age people report using it in the past year.
But Heitzeg says that her team's findings, and work by other addiction researchers, has shown that it can cause effects including problems with emotional functioning, academic problems, and even structural brain changes. And, the earlier in life someone tries marijuana, the faster their transition to becoming dependent on the drug, or other substances.
"Some people may believe that marijuana is not addictive or that it's 'better' than other drugs that can cause dependence," says Heitzeg, who is an assistant professor of psychiatry at the U-M Medical School and member of the U-M Addiction Research Center. "But this study provides evidence that it's affecting the brain in a way that may make it more difficult to stop using it. It changes your brain in a way that may change your behavior, and where you get your sense of reward from."
She is among the neuroscientists and psychologists leading a nationwide study called ABCD, for Adolescent Brain Cognitive Development. That study will track thousands of today's pre-teens nationwide over 10 years, looking at many aspects of their health and functioning, including brain development via brain scans. Since some of the teens in the study are likely to use marijuana, the study will provide a better chance of seeing what happens over time.
Story Source:
The above post is reprinted from materials provided by University of Michigan Health System. Note: Content may be edited for style and length.
Journal Reference:
- Meghan E. Martz, Elisa M. Trucco, Lora M. Cope, Jillian E. Hardee, Jennifer M. Jester, Robert A. Zucker, Mary M. Heitzeg. Association of Marijuana Use With Blunted Nucleus Accumbens Response to Reward Anticipation. JAMA Psychiatry, 2016; DOI: 10.1001/jamapsychiatry.2016.1161
http://www.uofmhealth.org/news/archive/201607/marijuana-use-dampens-brains-response-reward-over-time-u-m
Marijuana smokers 5 times more likely to develop an alcohol problem
Columbia University's Mailman School of Public Health / February 17, 2016
Summary : Adults who use marijuana are five times more likely to develop an alcohol use disorder (AUD) -- alcohol abuse or dependence -- compared with adults who do not use the drug. And adults who already have an alcohol use disorder and use marijuana are more likely to see the problem persist.
"'Our results suggest that cannabis use appears to be associated with an increased vulnerability to developing an alcohol use disorder, even among those without any history of this,' said Renee Goodwin, PhD, associate professor of Epidemiology at the Mailman School of Public Health."
"The researchers analyzed data from 27,461 adults enrolled in the National Epidemiologic Survey on Alcohol and Related Conditions who first used marijuana at a time when they had no lifetime history of alcohol use disorders."
https://www.sciencedaily.com/releases/2016/02/160217112847.htm
Columbia University's Mailman School of Public Health / February 17, 2016
Summary : Adults who use marijuana are five times more likely to develop an alcohol use disorder (AUD) -- alcohol abuse or dependence -- compared with adults who do not use the drug. And adults who already have an alcohol use disorder and use marijuana are more likely to see the problem persist.
"'Our results suggest that cannabis use appears to be associated with an increased vulnerability to developing an alcohol use disorder, even among those without any history of this,' said Renee Goodwin, PhD, associate professor of Epidemiology at the Mailman School of Public Health."
"The researchers analyzed data from 27,461 adults enrolled in the National Epidemiologic Survey on Alcohol and Related Conditions who first used marijuana at a time when they had no lifetime history of alcohol use disorders."
https://www.sciencedaily.com/releases/2016/02/160217112847.htm
Cannabis increases the noise in your brain
Biological Psychology / December 3, 2015
Several studies have demonstrated that the primary active constituent of cannabis, delta-9-tetrahydrocannabinol (∆9-THC), induces transient psychosis-like effects in healthy subjects similar to those observed in schizophrenia. However, the mechanisms underlying these effects are not clear.
A new study, published in the journal Biological Psychiatry, reports that ∆9-THC increases random neural activity, termed neural noise, in the brains of healthy human subjects. The findings suggest that increased neural noise may play a role in the psychosis-like effects of cannabis.
"At doses roughly equivalent to half or a single joint, ∆9-THC produced psychosis-like effects and increased neural noise in humans," explained senior author Dr. Deepak Cyril D'Souza, a Professor of Psychiatry at Yale School of Medicine.
"The dose-dependent and strong positive relationship between these two findings suggest that the psychosis-like effects of cannabis may be related to neural noise which disrupts the brain's normal information processing," added first author Dr. Jose Cortes-Briones, a Postdoctoral Associate in Psychiatry at Yale School of Medicine.
The investigators studied the effects of ∆9-THC on electrical brain activity in 24 human subjects who participated in a three-day study during which they received two doses of intravenous ∆9-THC or placebo in a double-blind, randomized, cross-over, and counterbalanced design.
If confirmed, the link between neural noise and psychosis could shed light on the biology of some of the symptoms associated with schizophrenia.
"This interesting study suggests a commonality between the effects on the brain of the major active ingredient in marijuana and symptoms of schizophrenia," stated Dr. John Krystal, Editor of Biological Psychiatry. "The impairment of cortical function by ∆9-THC could underlie some of the cognitive effects of marijuana. Not only does this finding aid our understanding of the processes underlying psychosis, it underscores an important concern in the debate surrounding medical and legalized access to marijuana."
https://www.sciencedaily.com/releases/2015/12/151203082207.htm
Biological Psychology / December 3, 2015
Several studies have demonstrated that the primary active constituent of cannabis, delta-9-tetrahydrocannabinol (∆9-THC), induces transient psychosis-like effects in healthy subjects similar to those observed in schizophrenia. However, the mechanisms underlying these effects are not clear.
A new study, published in the journal Biological Psychiatry, reports that ∆9-THC increases random neural activity, termed neural noise, in the brains of healthy human subjects. The findings suggest that increased neural noise may play a role in the psychosis-like effects of cannabis.
"At doses roughly equivalent to half or a single joint, ∆9-THC produced psychosis-like effects and increased neural noise in humans," explained senior author Dr. Deepak Cyril D'Souza, a Professor of Psychiatry at Yale School of Medicine.
"The dose-dependent and strong positive relationship between these two findings suggest that the psychosis-like effects of cannabis may be related to neural noise which disrupts the brain's normal information processing," added first author Dr. Jose Cortes-Briones, a Postdoctoral Associate in Psychiatry at Yale School of Medicine.
The investigators studied the effects of ∆9-THC on electrical brain activity in 24 human subjects who participated in a three-day study during which they received two doses of intravenous ∆9-THC or placebo in a double-blind, randomized, cross-over, and counterbalanced design.
If confirmed, the link between neural noise and psychosis could shed light on the biology of some of the symptoms associated with schizophrenia.
"This interesting study suggests a commonality between the effects on the brain of the major active ingredient in marijuana and symptoms of schizophrenia," stated Dr. John Krystal, Editor of Biological Psychiatry. "The impairment of cortical function by ∆9-THC could underlie some of the cognitive effects of marijuana. Not only does this finding aid our understanding of the processes underlying psychosis, it underscores an important concern in the debate surrounding medical and legalized access to marijuana."
https://www.sciencedaily.com/releases/2015/12/151203082207.htm
http://www.drugfree.org/join-together/almost-six-million-u-s-adults-experienced-marijuana-use-disorder-past-year-study/
Almost Six Million U.S. Adults Experienced Marijuana Use Disorder in Past Year: Study
"The study, published in the American Journal of Psychiatry, found 6.3 percent of adults acquire a dependence on marijuana at some point in their lives, and 2.5 percent of adults have experienced marijuana use disorder in the past year."
"Symptoms of marijuana use disorder include cravings, developing a tolerance, and experiencing withdrawal symptoms, including inability to sleep, nervousness, anger, or depression."
"The study found people with marijuana use disorder, particularly those with severe forms of the disorder, experience considerable mental disability. "
American Journal of Psychiatry / March 8, 2016
~ ~ ~ ~ ~ ~
The same research published in Science Daily adds:
"The percentage of Americans who reported using marijuana in the past year more than doubled between 2001-2002 and 2012-2013, and the increase in marijuana use disorders during that time was nearly as large."
"To be diagnosed with the disorder, individuals must meet at least two of 11 symptoms that assess craving, withdrawal, lack of control, and negative effects on personal and professional responsibilities. Severity of the disorder is rated as mild, moderate, or severe depending on the number of symptoms. As the severity of marijuana use disorder increased, so did associated disability levels and frequency of marijuana use."
"An increasing number of American adults do not perceive marijuana use as harmful," said Hasin. "While some can use marijuana without harms, other users do experience negative consequences, which can include mental and physical problems, and impaired functioning."
"'The new analysis complements previous population-level studies conducted by the National Institute on Alcohol Abuse and Alcoholism that show marijuana use can lead to harmful consequences for individuals and society,' said George F. Koob, PhD"
"The study authors note the urgency of identifying and implementing effective prevention and treatment for marijuana use disorder and call for more research to understand the combined effects of marijuana and alcohol. 'We feel strongly that more public education about the dangers associated with marijuana use is imperative,' stated Hasin. 'This is especially critical since we are learning more about public beliefs that marijuana use is harmless.'"
Almost Six Million U.S. Adults Experienced Marijuana Use Disorder in Past Year: Study
"The study, published in the American Journal of Psychiatry, found 6.3 percent of adults acquire a dependence on marijuana at some point in their lives, and 2.5 percent of adults have experienced marijuana use disorder in the past year."
"Symptoms of marijuana use disorder include cravings, developing a tolerance, and experiencing withdrawal symptoms, including inability to sleep, nervousness, anger, or depression."
"The study found people with marijuana use disorder, particularly those with severe forms of the disorder, experience considerable mental disability. "
American Journal of Psychiatry / March 8, 2016
~ ~ ~ ~ ~ ~
The same research published in Science Daily adds:
"The percentage of Americans who reported using marijuana in the past year more than doubled between 2001-2002 and 2012-2013, and the increase in marijuana use disorders during that time was nearly as large."
"To be diagnosed with the disorder, individuals must meet at least two of 11 symptoms that assess craving, withdrawal, lack of control, and negative effects on personal and professional responsibilities. Severity of the disorder is rated as mild, moderate, or severe depending on the number of symptoms. As the severity of marijuana use disorder increased, so did associated disability levels and frequency of marijuana use."
"An increasing number of American adults do not perceive marijuana use as harmful," said Hasin. "While some can use marijuana without harms, other users do experience negative consequences, which can include mental and physical problems, and impaired functioning."
"'The new analysis complements previous population-level studies conducted by the National Institute on Alcohol Abuse and Alcoholism that show marijuana use can lead to harmful consequences for individuals and society,' said George F. Koob, PhD"
"The study authors note the urgency of identifying and implementing effective prevention and treatment for marijuana use disorder and call for more research to understand the combined effects of marijuana and alcohol. 'We feel strongly that more public education about the dangers associated with marijuana use is imperative,' stated Hasin. 'This is especially critical since we are learning more about public beliefs that marijuana use is harmless.'"
http://www.sciencedaily.com/releases/2014/11/141116094332.htm
Secondhand marijuana smoke may damage blood vessels as much as tobacco smoke
"Breathing secondhand marijuana smoke could damage your heart and blood vessels as much as secondhand cigarette
smoke, according to preliminary research presented at the American Heart Association's Scientific Sessions 2014."
"Reduced blood vessel function may raise the chances of developing atherosclerosis and could lead to a heart attack".
"'Most people know secondhand cigarette smoke is bad for you, but many don't realize that secondhand marijuana smoke may also be harmful."
"There's no reason to think marijuana smoke is better than tobacco smoke. Avoid them both."
~ Matthew Springer, Ph.D.
"Marijuana and tobacco smoke are chemically and physically alike, aside from their active ingredients.
~ American Heart Association / November 16, 2014
Secondhand marijuana smoke may damage blood vessels as much as tobacco smoke
"Breathing secondhand marijuana smoke could damage your heart and blood vessels as much as secondhand cigarette
smoke, according to preliminary research presented at the American Heart Association's Scientific Sessions 2014."
"Reduced blood vessel function may raise the chances of developing atherosclerosis and could lead to a heart attack".
"'Most people know secondhand cigarette smoke is bad for you, but many don't realize that secondhand marijuana smoke may also be harmful."
"There's no reason to think marijuana smoke is better than tobacco smoke. Avoid them both."
~ Matthew Springer, Ph.D.
"Marijuana and tobacco smoke are chemically and physically alike, aside from their active ingredients.
~ American Heart Association / November 16, 2014
http://www.sciencedaily.com/releases/2014/11/141110161123.htm
Marijuana's long-term effects on the brain demonstrated
"Researchers for the first time comprehensively describe existing abnormalities in brain function and
structure of long-term marijuana users with multiple magnetic resonance imaging (MRI) techniques."
- Proceedings of the National Academy of Sciences / November 10, 2014
Marijuana's long-term effects on the brain demonstrated
"Researchers for the first time comprehensively describe existing abnormalities in brain function and
structure of long-term marijuana users with multiple magnetic resonance imaging (MRI) techniques."
- Proceedings of the National Academy of Sciences / November 10, 2014
http://www.sciencedaily.com/releases/2014/09/140930113117.htm
Adolescent exposure to THC may cause immune systems to go up in smoke
A team of Italian scientists have found that using marijuana in adolescence may do serious long-term damage to the immune system. This damage may result in autoimmune diseases and chronic inflammatory diseases, such as multiple sclerosis, inflammatory bowel disease and rheumatoid arthritis in adulthood.
"These studies not only point to adolescence as a key phase of immune system sensitivity, but also highlight the dramatic and
long lasting negative effects that a common recreational drug abused by teenagers may have on immune function."
- John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology
~ Journal of Leukocyte Biology / September 30, 2014
Adolescent exposure to THC may cause immune systems to go up in smoke
A team of Italian scientists have found that using marijuana in adolescence may do serious long-term damage to the immune system. This damage may result in autoimmune diseases and chronic inflammatory diseases, such as multiple sclerosis, inflammatory bowel disease and rheumatoid arthritis in adulthood.
"These studies not only point to adolescence as a key phase of immune system sensitivity, but also highlight the dramatic and
long lasting negative effects that a common recreational drug abused by teenagers may have on immune function."
- John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology
~ Journal of Leukocyte Biology / September 30, 2014
http://www.sciencedaily.com/releases/2014/09/140925150606.htm
The dangers of teens using marijuana
• "A potentially dangerous environment is being created where more preteens, teens and young adult are beginning to
use the substance with the feeling that it is safe."
• "Though public perception is that marijuana is a harmless drug, research is showing it can have a damaging impact on
developing brains and may lead to life-long addiction."
• "More high-schoolers in the U.S. now smoke marijuana than they do cigarettes."
•"Marijuana is the most common substance addiction being treated in adolescents in rehabilitation centers across the
country."
•"Research shows that heavy use can lead to neurotoxicity and alternations in brain development leading to: •
Impairment in thinking • Poor educational outcomes and perhaps a lower IQ • Increased likelihood of dropping out
of school • Symptoms of chronic bronchitis • Increased risk of psychosis disorders in those who are predisposed."
Loyola University Health System / September 25, 2014
The dangers of teens using marijuana
• "A potentially dangerous environment is being created where more preteens, teens and young adult are beginning to
use the substance with the feeling that it is safe."
• "Though public perception is that marijuana is a harmless drug, research is showing it can have a damaging impact on
developing brains and may lead to life-long addiction."
• "More high-schoolers in the U.S. now smoke marijuana than they do cigarettes."
•"Marijuana is the most common substance addiction being treated in adolescents in rehabilitation centers across the
country."
•"Research shows that heavy use can lead to neurotoxicity and alternations in brain development leading to: •
Impairment in thinking • Poor educational outcomes and perhaps a lower IQ • Increased likelihood of dropping out
of school • Symptoms of chronic bronchitis • Increased risk of psychosis disorders in those who are predisposed."
Loyola University Health System / September 25, 2014
http://www.sciencedaily.com/releases/2014/09/140902094103.htm
Cannabis withdrawal symptoms common among adolescents treated for substance use disorder
- "Although cannabis -- commonly known as marijuana -- is broadly believed to be nonaddictive, a study has found that
40 percent of cannabis-using adolescents receiving outpatient treatment for substance use disorder reported
experiencing symptoms of withdrawal, which are considered a hallmark of drug dependence."
- "Unfortunately, the general trend in attitudes in the U.S. is to minimize the risks and not recognize the addictiveness of
cannabis."
~ Massachusetts General Hospital, Department of Psychiatry, Center for Addiction Medicine / September 2, 2014
Cannabis withdrawal symptoms common among adolescents treated for substance use disorder
- "Although cannabis -- commonly known as marijuana -- is broadly believed to be nonaddictive, a study has found that
40 percent of cannabis-using adolescents receiving outpatient treatment for substance use disorder reported
experiencing symptoms of withdrawal, which are considered a hallmark of drug dependence."
- "Unfortunately, the general trend in attitudes in the U.S. is to minimize the risks and not recognize the addictiveness of
cannabis."
~ Massachusetts General Hospital, Department of Psychiatry, Center for Addiction Medicine / September 2, 2014
http://www.sciencedaily.com/releases/2014/09/140901085850.htm
Consequences of teen alcohol, marijuana use studied
"Marijuana use on the other hand was more commonly reported to compromise relationships with teachers or supervisors,
result in less energy or interest, and result in lower school or job performance."
~ New York University, Center for Drug Use and HIV Research / September 2, 2014
Consequences of teen alcohol, marijuana use studied
"Marijuana use on the other hand was more commonly reported to compromise relationships with teachers or supervisors,
result in less energy or interest, and result in lower school or job performance."
~ New York University, Center for Drug Use and HIV Research / September 2, 2014
http://www.sciencedaily.com/releases/2014/08/140809141436.htm
Regular marijuana use bad for teens' brains, study finds
"Frequent marijuana use can have a significant negative effect on the brains of teenagers and young adults, including cognitive
decline, poor attention and memory, and decreased IQ."
~ American Psychological Association / August 9, 2014
Regular marijuana use bad for teens' brains, study finds
"Frequent marijuana use can have a significant negative effect on the brains of teenagers and young adults, including cognitive
decline, poor attention and memory, and decreased IQ."
~ American Psychological Association / August 9, 2014
http://www.sciencedaily.com/releases/2014/06/140623120051.htm
Prescription drugs overtake cannabis in fatal crashes
"A study shows that more drivers are now testing positive for prescription drugs, cannabis, and multiple drugs, and
they are more likely to be older than 50. The study finds that the percentage of drugged drivers with three or more
drugs in their system nearly doubled from 1993 to 2010."
"We're also seeing more and more people using drugs and alcohol together. About 70 percent of drivers who tested
positive for cocaine had also been consuming alcohol, and almost 55 percent of drivers who tested positive for
cannabis also had alcohol in their systems."
University of Nebraska Medical Center / June 23, 2014
Prescription drugs overtake cannabis in fatal crashes
"A study shows that more drivers are now testing positive for prescription drugs, cannabis, and multiple drugs, and
they are more likely to be older than 50. The study finds that the percentage of drugged drivers with three or more
drugs in their system nearly doubled from 1993 to 2010."
"We're also seeing more and more people using drugs and alcohol together. About 70 percent of drivers who tested
positive for cocaine had also been consuming alcohol, and almost 55 percent of drivers who tested positive for
cannabis also had alcohol in their systems."
University of Nebraska Medical Center / June 23, 2014
http://www.sciencedaily.com/releases/2014/06/140606091427.htm
First case of catatonic psychosis caused by consumption of Spice described by researchers
"The first case of catatonic psychosis caused by a synthetic derivate of Cannabis, Spice, has been described by researchers. The
relation between the consumption of this substance, a psychotic break and some locomotor system problems, similar to the ones
caused by Parkinson's, have also been described for the first time."
~ Asociación RUVID / June 6, 2014
First case of catatonic psychosis caused by consumption of Spice described by researchers
"The first case of catatonic psychosis caused by a synthetic derivate of Cannabis, Spice, has been described by researchers. The
relation between the consumption of this substance, a psychotic break and some locomotor system problems, similar to the ones
caused by Parkinson's, have also been described for the first time."
~ Asociación RUVID / June 6, 2014
http://www.sciencedaily.com/releases/2014/06/140605093311.htm
Research on marijuana's negative health effects summarized in report
"The review describes the science establishing that marijuana can be addictive and that this risk for addiction increases for daily
or young users."
"The authors review literature showing that marijuana impairs driving, increasing the risk of being involved in a car accident."
"Research suggests that marijuana impairs critical thinking and memory functions during use and that these deficits persist for
days after using. In addition, a long-term study showed that regular marijuana use in the early teen years lowers IQ into
adulthood."
~ NIH/National Institute on Drug Abuse / June 5, 2014
Research on marijuana's negative health effects summarized in report
"The review describes the science establishing that marijuana can be addictive and that this risk for addiction increases for daily
or young users."
"The authors review literature showing that marijuana impairs driving, increasing the risk of being involved in a car accident."
"Research suggests that marijuana impairs critical thinking and memory functions during use and that these deficits persist for
days after using. In addition, a long-term study showed that regular marijuana use in the early teen years lowers IQ into
adulthood."
~ NIH/National Institute on Drug Abuse / June 5, 2014
http://www.sciencedaily.com/releases/2014/06/140602102013.htm
Marijuana use associated with impaired sleep quality
"Marijuana use is associated with impaired sleep quality, research suggests. Results show that any history of cannabis
use was associated with an increased likelihood of reporting difficulty falling asleep, struggling to maintain sleep,
experiencing non-restorative sleep, and feeling daytime sleepiness."
"The results suggest that initiation of marijuana use in adolescence may impart a higher risk for subsequent insomnia
symptoms."
American Academy of Sleep Medicine / June 2, 2014
Marijuana use associated with impaired sleep quality
"Marijuana use is associated with impaired sleep quality, research suggests. Results show that any history of cannabis
use was associated with an increased likelihood of reporting difficulty falling asleep, struggling to maintain sleep,
experiencing non-restorative sleep, and feeling daytime sleepiness."
"The results suggest that initiation of marijuana use in adolescence may impart a higher risk for subsequent insomnia
symptoms."
American Academy of Sleep Medicine / June 2, 2014