Janet E. Joy, Stanley J. Watson, Jun Borras, Sebastian Scholl , John A. Benson, Wendy Wolford
01 January 1999
The medical use of marijuana is surrounded by a cloud of social, political, and religious controversy, which obscures the facts that should be considered in the debate. This book summarizes what we know about marijuana from evidence-based medicine--the harm it may do and the relief it may bring to patients. The book helps the reader understand not only what science has to say about medical marijuana but also the logic behind the scientific conclusions.
This study examines the current knowledge of physiological and clinical effects of tetrahydrocannabinol (THC) and cannabidiol (CBD) and presents a rationale for their combination in pharmaceutical preparations. Cannabinoid and vanilloid receptor effects as well as non-receptor mechanisms are explored, such as the capability of THC and CBD to act as anti-inflammatory substances independent of cyclo-oxygenase (COX) inhibition. CBD is demonstrated to antagonise some undesirable effects of THC including intoxication, sedation and tachycardia, while contributing analgesic, anti-emetic, and anti-carcinogenic properties in its own right.
The largest study of its kind has unexpectedly concluded that smoking marijuana, even regularly and heavily, does not lead to lung cancer. The new findings "were against our expectations," said Donald Tashkin of the University of California at Los Angeles, a pulmonologist who has studied marijuana for 30 years. Marijuana also contains the chemical THC, which he said may kill aging cells and keep them from becoming cancerous.
A UCSF study suggests patients with chronic pain may experience greater relief if their doctors add cannabinoids - the main ingredient in cannabis or medical marijuana - to an opiates-only treatment. The findings, from a small-scale study, also suggest that a combined therapy could result in reduced opiate dosages. Cannabidiol, or CBD, appears to be very effective against pain and inflammation without creating the "high" created by THC.
New research finds that the two main ingredients in marijuana have opposing effects on it. The study examined 15 normal men who had previously smoked cannabis only a few times. Researchers exposed the men to each of the two most psychoactive ingredients in marijuana — delta-9 tetrahydrocannabinol (THC) and cannabidiol (CBD) and compared their effects with those of a placebo while the participants performed a mental task.
Marijuana has been shown to have both anxiolytic (anti-anxiety) effects and to induce anxiety and psychosis in certain people. In schizophrenics, it can increase symptoms, and in healthy people it can increase the risk of schizophrenia. Now, new study shows that the two active ingredients in pot, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) may have quite opposite effects on the brain – and behavior – and could explain why pot’s effects can be unpredictable.
The legal status of cannabis for personal use is one of the most controversial policy issues in the European Union. Although cannabis is a classified narcotic drug placed under control by the United Nations and by all EU Member States, the measures adopted to control it at national level vary considerably, as shown in the table, click here to access the information country by country.
A compound found in marijuana can treat schizophrenia as effectively as antipsychotic medications, with far fewer side effects, according to a preliminary clinical trial. Unlike the main ingredient in marijuana, THC, which can produce psychotic reactions and may worsen schizophrenia, cannabidiol (CBD) has antipsychotic effects, according to previous research in both animals and humans.
There is a growing body of evidence to support the use of medical cannabis as an adjunct to or substitute for prescription opiates in the treatment of chronic pain. When used in conjunction with opiates, cannabinoids lead to a greater cumulative relief of pain, resulting in a reduction in the use of opiates (and associated side-effects) by patients in a clinical setting. Additionally, cannabinoids can prevent the development of tolerance to and withdrawal from opiates, and can even rekindle opiate analgesia after a prior dosage has become ineffective.
Prosecutors and crime-lab scientists say a little-noticed provision in Washington’s new law legalizing recreational marijuana has jeopardized their ability to go after any pot crimes at all, and they’re calling for an immediate fix in the Legislature. The group is suggesting a change in the legal definition of marijuana.
Thanks in part to the Netherlands' policy of marijuana decriminalization, there are people living in the Dutch city of Utrecht whose addiction to cannabis prevents them from getting effective treatment for mental illness. According to a September 10 statement from Utrecht Mayor Wolfsen, "There is a group of about eighty people with a chronic psychotic disorder who barely respond to their treatment. A possible explanation for this is their severe dependence [on] cannabis."
Cannabis is associated with psychosis (a symptom) and schizophrenia (an illness where this symptom is persistent) in complex, contradictory and mysterious ways. The evidence does demonstrate various links that we all should all be aware of, especially cannabis users and parents. However, the evidence does not support anything like the level of fear propagated in the media.
A Colorado marijuana innovation is changing the way lawmakers in even the most conservative parts of the country talk about cannabis and is poised to create a rapid expansion in the number of states that have legalized marijuana in some way. But many marijuana advocates view the new political campaign with skepticism, fearing it could halt their movement's momentum. Taken to its logical conclusion, medical marijuana could be a "box canyon" for broader legalization efforts.
That cannabis and schizophrenia are linked is widely accepted. Several studies suggest the drug can set off short-term psychotic episodes in those already suffering from the condition. Other research, though, does more than this. It shows that people with schizophrenia are twice as likely as others to use cannabis. This leads some to argue that the drug is actually a cause of schizophrenia rather than just a trigger—a line of evidence sometimes employed by those who wish to keep it illegal.
Dr David Potter and GW Pharmaceuticals – a company that is exploring how cannabis could help treat a range of illnesses ranging from epilepsy to cancer – have turned their attention to developing a cannabis-based treatment for psychosis and related illnesses such as schizophrenia. For a drug that is widely seen as a trigger for acute psychotic illness in young users, this at first sounds preposterous. But, as Potter explains, the cannabis plant is much more than just a psychedelic weed. A cannabinoid known as CBD (or cannabidiol) appears to have almost the exact opposite effect.