http://www.sciencedaily.com/news/mind_brain/marijuana/ Medical research on marijuana. How does marijuana affect the brain? What are some of the risks? Could ingredients in marijuana treat disease? Read this and more. en-us Sat, 11 Oct 2008 19:05:01 EDT Sat, 11 Oct 2008 19:05:01 EDT 60 http://www.sciencedaily.com/images/logosmall.gif http://www.sciencedaily.com/news/mind_brain/marijuana/ For more science articles, visit ScienceDaily. http://www.sciencedaily.com/releases/2008/10/081010175311.htm While many congregations of different faiths preach against drug abuse, it has been unclear whether a youth's religious involvement has any effect on his risk of drug abuse. Now a new national study finds that religious involvement makes teens half as likely to use marijuana. Fri, 10 Oct 2008 00:00:00 EDT http://www.sciencedaily.com/releases/2008/10/081010175311.htm http://www.sciencedaily.com/releases/2008/10/081001093237.htm A new study shows that adolescent insomnia symptoms are associated with depression, suicide ideation and attempts, and the use of alcohol, cannabis and other drugs such as cocaine. Sun, 05 Oct 2008 14:00:00 EDT http://www.sciencedaily.com/releases/2008/10/081001093237.htm http://www.sciencedaily.com/releases/2008/09/080916154721.htm Scientists have studied the effects of a drug that reduces the progression of a disease similar to multiple sclerosis in animals. This discovery represents another step in the standing fight against the disease. Fri, 19 Sep 2008 05:00:00 EDT http://www.sciencedaily.com/releases/2008/09/080916154721.htm http://www.sciencedaily.com/releases/2008/09/080912091728.htm A new type of drug could alleviate pain in a similar way to cannabis without affecting the brain, according to a new study in the journal Pain. The research demonstrates for the first time that cannabinoid receptors called CB2, which can be activated by cannabis use, are present in human sensory nerves in the peripheral nervous system, but are not present in a normal human brain. Sun, 14 Sep 2008 08:00:00 EDT http://www.sciencedaily.com/releases/2008/09/080912091728.htm http://www.sciencedaily.com/releases/2008/08/080820163231.htm New research provides evidence that one of the only naturally occurring fatty acids in the brain can help to protect brain cells from neurodegenerative diseases like Alzheimer's and Parkinson's. Fri, 22 Aug 2008 02:00:00 EDT http://www.sciencedaily.com/releases/2008/08/080820163231.htm http://www.sciencedaily.com/releases/2008/08/080806113135.htm In a double-blind, placebo-controlled clinical trial to assess the impact of smoked medical cannabis, or marijuana, on the neuropathic pain associated with HIV, researchers have found that reported pain relief was greater with cannabis than with a placebo. Thu, 07 Aug 2008 23:00:00 EDT http://www.sciencedaily.com/releases/2008/08/080806113135.htm http://www.sciencedaily.com/releases/2008/07/080721114608.htm CUPID is a clinical trial which will evaluate whether tetrahydrocannabinol (THC), one of many compounds found in the in the cannabis plant (and the main active ingredient) is able to slow the progression of MS. This is an important study for people with MS because current treatments either target the immune system in the early stages of MS, or are aimed at easing specific symptoms such as muscle spasms or bladder problems. At present there is no treatment which slows progression of the disease. Mon, 21 Jul 2008 00:00:00 EDT http://www.sciencedaily.com/releases/2008/07/080721114608.htm http://www.sciencedaily.com/releases/2008/07/080714192555.htm Research exploring new ways of exploiting the full medicinal uses of cannabis while avoiding unwanted side-effects. Cannabis is a source of compounds known as cannabinoids, one of which, THC -- the main chemical responsible for the 'high' -- has long been licensed as a medicine for suppressing nausea produced by chemotherapy and for stimulating appetite, for instance, in AIDS patients. Tue, 15 Jul 2008 23:00:00 EDT http://www.sciencedaily.com/releases/2008/07/080714192555.htm http://www.sciencedaily.com/releases/2008/07/080707161411.htm Researchers report that alterations in a molecular brain pathway activated by marijuana, called cannabinoid 1 receptor, may contribute to the cognitive symptoms of schizophrenia, suggesting possible new drug targets that could help to improve functioning and memory in people with the mental illness. Expression of CB1R, the site of action of the main chemical ingredient of marijuana, is significantly reduced in the brains of individuals with schizophrenia. Tue, 08 Jul 2008 11:00:00 EDT http://www.sciencedaily.com/releases/2008/07/080707161411.htm http://www.sciencedaily.com/releases/2008/07/080702160944.htm Scientists have discovered that our own body not only makes chemical compounds similar to the active ingredient in marijuana, but these play an important part in maintaining healthy skin. This finding on "endocannabinoids" could lead to new drugs that treat skin conditions ranging from acne to dry skin, and even skin-related tumors. Thu, 03 Jul 2008 17:00:00 EDT http://www.sciencedaily.com/releases/2008/07/080702160944.htm http://www.sciencedaily.com/releases/2008/06/080630201007.htm A survey of 17 countries has found that despite its punitive drug policies the United States has the highest levels of illegal cocaine and cannabis use. Cannabis use was highest in the US (42.4%). Drug use "does not appear to be simply related to drug policy," say the authors, "since countries with more stringent policies towards illegal drug use did not have lower levels of such drug use than countries with more liberal policies." In the Netherlands, for example, which has more liberal policies than the US, 19.8% reported cannabis use. Tue, 01 Jul 2008 08:00:00 EDT http://www.sciencedaily.com/releases/2008/06/080630201007.htm http://www.sciencedaily.com/releases/2008/06/080626150628.htm The growing body of evidence that marijuana (cannabis) may be effective as a pain reliever has been expanded with publication of a new study in The Journal of Pain reporting that patients with nerve pain showed reduced pain intensity from smoking marijuana. Researchers examined whether marijuana produces analgesia for patients with neuropathic pain. Thirty-eight patients were examined. They were given either high-dose (7%), low-dose (3.5%) or placebo cannabis. Sun, 29 Jun 2008 08:00:00 EDT http://www.sciencedaily.com/releases/2008/06/080626150628.htm http://www.sciencedaily.com/releases/2008/06/080624151827.htm Oral cannabis (a form of medical marijuana) not only failed to alleviate certain types of pain in human volunteers but, surprisingly, it instead caused increased sensitivity to some forms of pain. Researchers evaluated the analgesic potency of orally administered cannabis extract that included its main psychoactive component, Tetrahydrocannabinol (THC). Wed, 25 Jun 2008 14:00:00 EDT http://www.sciencedaily.com/releases/2008/06/080624151827.htm http://www.sciencedaily.com/releases/2008/06/080617125751.htm Claims that a large increase in the strength of cannabis over the last decade is driving the occurrence of mental health and other problems for users are not borne out by a study of the worldwide literature, say researchers at the National Drug and Alcohol Research Centre and the National Drug Research Institute, both from Australia. Thu, 19 Jun 2008 08:00:00 EDT http://www.sciencedaily.com/releases/2008/06/080617125751.htm http://www.sciencedaily.com/releases/2008/06/080616170831.htm Researchers have determined that medical use of cannabinoids do not cause an increase in serious adverse events, but are associated with an increase in some non-serious adverse events. Of all non-serious adverse events, dizziness was the most common. Tue, 17 Jun 2008 11:00:00 EDT http://www.sciencedaily.com/releases/2008/06/080616170831.htm http://www.sciencedaily.com/releases/2008/06/080610071947.htm In the first study across time into late childhood of the effects of prenatal drug exposure on sleep, prenatal drug exposure is associated with greater sleep problems in children. In addition, nicotine has a unique effect, and early sleep problems predict later sleep problems. Tue, 10 Jun 2008 00:00:00 EDT http://www.sciencedaily.com/releases/2008/06/080610071947.htm http://www.sciencedaily.com/releases/2008/06/080602160845.htm Long-term, heavy cannabis use may be associated with structural abnormalities in areas of the brain known as the hippocampus and amygdala, according to a new article in the Archives of General Psychiatry. Tue, 03 Jun 2008 20:00:00 EDT http://www.sciencedaily.com/releases/2008/06/080602160845.htm http://www.sciencedaily.com/releases/2008/05/080516094438.htm Researchers may have unlocked the key to better understanding the effect addictive drugs have on the human brain. Researchers discovered that a drug that works through the cannabinoid 1 receptor recognizing the active ingredient of marijuana activates many different transcription factors, triggering the differentiation of neurons, causing permanent changes in a person's brain. Sun, 18 May 2008 20:00:00 EDT http://www.sciencedaily.com/releases/2008/05/080516094438.htm http://www.sciencedaily.com/releases/2008/05/080514111721.htm A variety of middle-class people are making a conscious but careful choice to use marijuana to enhance their leisure activities. A qualitative study showed that there is no such thing as a 'typical' marijuana user, but that people of all ages are selectively lighting up the drug as a way to enhance activities ranging from watching television and playing sports to having sex, painting or writing. Thu, 15 May 2008 02:00:00 EDT http://www.sciencedaily.com/releases/2008/05/080514111721.htm http://www.sciencedaily.com/releases/2008/05/080513054830.htm Marijuana abuse leads to blood flow problems in the brain and increased risks for heart problems. To understand the way that marijuana might cause these side-effects, NIH scientists measured proteins in the blood of marijuana abusers and found that heavy marijuana users show increased levels of a protein called apolipoprotein CIII which can cause increases in blood triglyceride levels. These findings might explain why marijuana users suffer from brain and cardiac problems. Tue, 13 May 2008 23:00:00 EDT http://www.sciencedaily.com/releases/2008/05/080513054830.htm http://www.sciencedaily.com/releases/2008/05/080509105348.htm Millions of American teens report experiencing weeks of hopelessness and loss of interest in normal daily activities and many of these depressed teens are using marijuana and other drugs, making their situation worse, according to a new White House report. Sat, 10 May 2008 20:00:00 EDT http://www.sciencedaily.com/releases/2008/05/080509105348.htm http://www.sciencedaily.com/releases/2008/05/080508222420.htm Teenagers and young adults across Europe drink and take drugs as part of deliberate sexual strategies. A third of 16-35 year old males and a quarter of females surveyed are drinking alcohol to increase their chances of sex, while cocaine, ecstasy and cannabis are intentionally used to enhance sexual arousal or prolong sex. Fri, 09 May 2008 20:00:00 EDT http://www.sciencedaily.com/releases/2008/05/080508222420.htm http://www.sciencedaily.com/releases/2008/05/080507133326.htm Anti-obesity drugs that work by blocking brain molecules similar to those in marijuana could also interfere with neural development in young children, according to a new study from MIT's Picower Institute for Learning and Memory. Thu, 08 May 2008 05:00:00 EDT http://www.sciencedaily.com/releases/2008/05/080507133326.htm http://www.sciencedaily.com/releases/2008/04/080418154959.htm Right now, about half of all people who take medicine for an anxiety disorder don't get much help from it. And doctors have no definitive way to predict who will, and who won't, benefit from each antianxiety prescription they write. Scientists are working to bring more certainty to anxiety treatment, by probing the connection between brain activity, genetics and medication. Tue, 22 Apr 2008 02:00:00 EDT http://www.sciencedaily.com/releases/2008/04/080418154959.htm http://www.sciencedaily.com/releases/2008/04/080414103611.htm A new report from the Centre For Addiction and Mental Health reveals both promising substance use trends and public health flags. The study noted a substantial increase in cannabis use among Ontario adults. Also, past year smoking rates are the lowest on record, significantly declining from 28 percent in 1996 to 20 percent in 2005. Rates of drinking and driving have steadily declined from 13 percent in 1996 to just 6 percent in 2005. Mon, 14 Apr 2008 00:00:00 EDT http://www.sciencedaily.com/releases/2008/04/080414103611.htm http://www.sciencedaily.com/releases/2008/04/080408150512.htm Marijuana is among the most frequently used illicit drugs by women during their childbearing years and there is growing concern that marijuana abuse during pregnancy, either alone or in combination with other drugs, may have serious effects on fetal brain development. There is strong evidence that THC, the main psychoactive component of marijuana, crosses the placenta, that maternal marijuana abuse results in intrauterine growth retardation and that infants exposed to marijuana exhibit a temporary syndrome that includes lethargy and decreased muscle tone. A new study using rats found that THC combined with mildly intoxicating doses of alcohol induced widespread nerve cell death in the brain. Fri, 11 Apr 2008 14:00:00 EDT http://www.sciencedaily.com/releases/2008/04/080408150512.htm http://www.sciencedaily.com/releases/2008/04/080407153034.htm Over 1 million babies born annually in the United States are exposed to drugs, alcohol or tobacco while in utero. New research suggests that prenatal exposure to these substances (alone or in combination) may have effects on the baby's brain structure that persist into adolescence. Tue, 08 Apr 2008 08:00:00 EDT http://www.sciencedaily.com/releases/2008/04/080407153034.htm http://www.sciencedaily.com/releases/2008/04/080401095221.htm A new study finds that references to illegal drug use in rap music jumped sixfold in the two decades since 1979, the year when rap made its way from inner-city urban areas to a mainstream audience. Moreover, illegal drug use became increasingly linked during this period to wealth, glamor and social standing, raising red flags about its potential influence on young listeners, said the study author. Tue, 01 Apr 2008 00:00:00 EDT http://www.sciencedaily.com/releases/2008/04/080401095221.htm http://www.sciencedaily.com/releases/2008/03/080326121235.htm The brain cells called astrocytes, and not just neurons, are sensitive to the substances called cannabinoids -- the active chemicals in marijuana. The researchers said their findings could aid in development of treatments for cannabinoid drug abuse. Thu, 27 Mar 2008 02:00:00 EDT http://www.sciencedaily.com/releases/2008/03/080326121235.htm http://www.sciencedaily.com/releases/2008/03/080320095045.htm Despite public health campaigns, a surprising number of women continue to use substances such as tobacco, marijuana and alcohol during pregnancy and their usage rebounds to pre-pregnancy levels within two years of having a baby. Dads, meanwhile, don't get the messages at all. Fri, 21 Mar 2008 08:00:00 EDT http://www.sciencedaily.com/releases/2008/03/080320095045.htm http://www.sciencedaily.com/releases/2008/03/080311165905.htm Researchers have teased out two distinct sets of risk factors for head and neck cancers, suggesting that there are two completely different kinds of the disease. Sex practices and lifestyle are culprits. Head and neck tumors caused by the human papillomavirus (HPV), a common sexually transmitted virus, were most often linked to certain sexual behaviors and marijuana use, rather than tobacco and alcohol. Thu, 13 Mar 2008 17:00:00 EDT http://www.sciencedaily.com/releases/2008/03/080311165905.htm http://www.sciencedaily.com/releases/2008/03/080307110348.htm Smokers trying to quit in the future could do it with the help of cannabis based medicines, according to new research. Teams of pharmacologists, studying the cannabis-like compounds which exist naturally in our bodies (endocannabinoids), are exploring the potential for medical treatment. This includes treating conditions as diverse as obesity, diabetes, depression and addiction to substances like nicotine. Mon, 10 Mar 2008 14:00:00 EDT http://www.sciencedaily.com/releases/2008/03/080307110348.htm http://www.sciencedaily.com/releases/2008/03/080304075727.htm The risk of marijuana use among deviance-prone males goes up or down with national trends. But deviance prone girls are just as likely to use marijuana during years of high and low national use. Wed, 05 Mar 2008 05:00:00 EST http://www.sciencedaily.com/releases/2008/03/080304075727.htm http://www.sciencedaily.com/releases/2008/02/080217214547.htm Patients with fibromyalgia treated with a synthetic form of marijuana, nabilone, showed significant reductions in pain and anxiety in a first-of-its-kind study. Fibromyalgia syndrome has no cure, is difficult to diagnose, and effective pain management strategies are a must to help patients cope with the disease. An estimated 12 million Americans have fibromyalgia, which is characterized by widespread muscle and joint pain and myriad other symptoms. The condition is far more prevalent in women and the incidence increases with age, reaching 7 percent among women 65 years and older. Mon, 18 Feb 2008 23:00:00 EST http://www.sciencedaily.com/releases/2008/02/080217214547.htm http://www.sciencedaily.com/releases/2008/02/080213160851.htm People with multiple sclerosis who smoke marijuana are more likely to have emotional and memory problems, according to new research. The study found marijuana smokers performed 50 percent slower on tests of information processing speed compared to MS patients who did not smoke marijuana. There was also a significant association between smoking marijuana and emotional problems such as depression and anxiety. Thu, 14 Feb 2008 14:00:00 EST http://www.sciencedaily.com/releases/2008/02/080213160851.htm http://www.sciencedaily.com/releases/2008/01/080124145015.htm Research by a group of scientists studying the effects of heavy marijuana use suggests that withdrawal from the use of marijuana is similar to what is experienced by people when they quit smoking cigarettes. Abstinence from each of these drugs appears to cause several common symptoms, such as irritability, anger and trouble sleeping -- based on self reporting in a recent study of 12 heavy users of both marijuana and cigarettes. Fri, 25 Jan 2008 05:00:00 EST http://www.sciencedaily.com/releases/2008/01/080124145015.htm http://www.sciencedaily.com/releases/2008/01/080108133347.htm The first clinical studies of an experimental drug have revealed that obese people who take it for 12 weeks lose weight, even at very low doses. Short-term studies also suggest that the drug, called taranabant -- the second drug designed to fight obesity by blocking cannabinoid receptors in the brain -- seems to cause people to consume fewer calories and burn more energy. Thu, 10 Jan 2008 17:00:00 EST http://www.sciencedaily.com/releases/2008/01/080108133347.htm http://www.sciencedaily.com/releases/2007/12/071218113506.htm What are University students' motivations for using or not using cannabis? Researchers found various factors that might encourage use. Compared to non-users, users believed more strongly that cannabis would help them fit in with their friends, feel relaxed, forget their worries, and enjoy themselves. They also believed that their friends would approve of their use. Wed, 19 Dec 2007 08:00:00 EST http://www.sciencedaily.com/releases/2007/12/071218113506.htm http://www.sciencedaily.com/releases/2007/12/071217110328.htm Here's another reason to "keep off the grass." Researchers report that marijuana smoke contains significantly higher levels of several toxic compounds -- including ammonia and hydrogen cyanide -- than tobacco smoke and may therefore pose similar health risks. The scientists found that ammonia levels were 20 times higher in the marijuana smoke than in the tobacco smoke, while hydrogen cyanide, nitric oxide and certain aromatic amines occurred at levels 3-5 times higher in the marijuana smoke, they say. Tue, 18 Dec 2007 11:00:00 EST http://www.sciencedaily.com/releases/2007/12/071217110328.htm http://www.sciencedaily.com/releases/2007/11/071129151109.htm Scientists have discovered a new way to separate the therapeutic benefits of cannabis from its mood-altering side-effects. Cannabis contains a chemical called THC, which binds to, and activates, proteins in the brain known as 'CB1 cannabinoid receptors'. Activating these receptors can relieve pain and prevent epileptic seizures; but it also causes the mood-altering effect experienced by people who use cannabis as a recreational drug. Fri, 30 Nov 2007 02:00:00 EST http://www.sciencedaily.com/releases/2007/11/071129151109.htm http://www.sciencedaily.com/releases/2007/11/071105120556.htm Researchers have found that boosting the amounts of a marijuana-like brain transmitter called anandamide produces antidepressant effects in test rats. Wed, 07 Nov 2007 14:00:00 EST http://www.sciencedaily.com/releases/2007/11/071105120556.htm http://www.sciencedaily.com/releases/2007/11/071105164459.htm The genes that play a role in illegal drug abuse are not entirely the same as those involved in dependence on legal substances like alcohol and nicotine, and caffeine addiction appears to be genetically independent of all the others, according to a new study. Wed, 07 Nov 2007 02:00:00 EST http://www.sciencedaily.com/releases/2007/11/071105164459.htm http://www.sciencedaily.com/releases/2007/11/071105164453.htm A Swiss study suggests that teens who use only cannabis appear to function better than those who also use tobacco, and are more socially driven and have no more psychosocial problems than those who abstain from both substances, according to a new report. Tue, 06 Nov 2007 14:00:00 EST http://www.sciencedaily.com/releases/2007/11/071105164453.htm http://www.sciencedaily.com/releases/2007/11/071102091207.htm New research carried out with psychology students suggests a possible relation between what some call "emotional intelligence" and the use of tobacco and cannabis. According to the research, students who had started smoking either tobacco or cannabis at a younger age and who regularly smoked these substances obtained lower scores in questions related to emotional regulation. Sat, 03 Nov 2007 08:00:00 EDT http://www.sciencedaily.com/releases/2007/11/071102091207.htm http://www.sciencedaily.com/releases/2007/10/071025080834.htm Addiction research suggests that most parents are aware of and accurately evaluate the extent of their teenager's cigarette smoking, marijuana use, drinking and overall substance use. Fri, 26 Oct 2007 20:00:00 EDT http://www.sciencedaily.com/releases/2007/10/071025080834.htm http://www.sciencedaily.com/releases/2007/10/071024141745.htm Smoked cannabis eased pain induced in healthy volunteers, according to a new study. However, the researchers found that less may be more. The subjects were healthy volunteers who inhaled either medical cannabis or a placebo after pain was induced. Thu, 25 Oct 2007 02:00:00 EDT http://www.sciencedaily.com/releases/2007/10/071024141745.htm http://www.sciencedaily.com/releases/2007/10/071023183937.htm A new neurobiological study has found that a synthetic form of THC, the active ingredient in cannabis, is an effective anti-depressant at low doses. However, at higher doses, the effect reverses itself and can actually worsen depression and other psychiatric conditions like psychosis. Wed, 24 Oct 2007 14:00:00 EDT http://www.sciencedaily.com/releases/2007/10/071023183937.htm http://www.sciencedaily.com/releases/2007/10/071014163644.htm Cannabis (marijuana) is the most widely produced plant-based illicit drug worldwide and the illegal drug most frequently used in Europe. Its use increased in almost all EU countries during the 1990s, in particular among young people, including school students. Cannabis use is highest among 15- to 24-year-olds, with lifetime prevalence ranging for most countries from 20 -- 40%. Recently there has been a new surge in the level of concern about potential social and health outcomes of cannabis use, although the available evidence still does not provide a clear-cut understanding of the issues. Mon, 15 Oct 2007 14:00:00 EDT http://www.sciencedaily.com/releases/2007/10/071014163644.htm