Whether marijuana helps with pain is unclear

Daily users with severe pain report worsening health

April 8, 2020

Science Daily/Ohio State University

Medical marijuana users who say they have high levels of pain are more likely than those with low pain to say they use cannabis three or more times a day, a new study finds.

However, daily marijuana users with severe pain also reported their health had become worse in the past year.

The results don't necessarily mean that marijuana is not effective in treating at least some kinds of pain, according to the researchers. But it suggests more research is needed before marijuana is accepted as an effective treatment for severe pain.

"It's not clear if marijuana is helping or not," said Bridget Freisthler, co-author of the study and professor of social work at The Ohio State University.

"The benefits aren't as clear-cut as some people assume."

The study was published recently in the International Journal of Drug Policy.

One issue is the complex relationship between pain, marijuana use and self-reported health, said Alexis Cooke, lead author of the study and postdoctoral scholar in psychiatry at the University of California, San Francisco.

"Having high chronic pain is related to poorer health, so it may be that people who are using marijuana more often already had worse health to begin with," Cooke said.

"There are still a lot of questions to answer."

The study involved a survey of 295 medical marijuana dispensary patients in Los Angeles. The surveys were conducted in 2013, when California allowed marijuana use only for medical purposes.

All participants were asked how often they used marijuana; rated how their current health compared to one year ago (on a five-point scale from "much better" to "much worse"); and were asked two questions about their pain levels. Based on their answers, the researchers rated participants' pain as low, moderate or high.

Among those surveyed, 31 percent reported high pain, 24 percent moderate pain, and 44 percent were in the low-pain category.

Daily marijuana use was reported by 45 percent of the sample, and 48 percent said they used three or more times per day.

The percentage of participants who used marijuana every day did not differ by pain categories. But about 60 percent of those who reported high pain used the drug three or more times a day, compared to 51 percent of those with moderate pain and 39 percent of those in the low-pain group.

Findings showed no association between daily marijuana use and change in health status among those with low levels of pain. But daily marijuana use was linked to worsening health status among those reporting high levels of pain.

However, strangely, there was no association between how often participants used marijuana per day and changes in health status. There's no easy explanation for this, Freisthler said.

"It shows how little we know about marijuana as medicine, how people are using it, the dosages they are receiving and its long-term effects," she said.

People use marijuana for a variety of different types of pain, including cancer, joint pain, HIV and nerve pain. Researchers don't know if marijuana has different effects on different causes of pain, Cooke said.

"Chronic pain is also associated with depression and anxiety. Marijuana may help with these problems for some people, even if it doesn't help with the pain," she said.

In addition, marijuana use seems to help people who have lost their appetite due to pain or nausea caused by cancer drugs.

"It may not be the pain that patients are trying to address," Cooke said.

The results do suggest we need to know more about the link between marijuana and pain relief, Freisthler said.

"Particularly since the opioid crisis, some people have been touting marijuana as a good substitute for opioids for people in pain," she said.

"But our study suggests we don't know that marijuana is helping to address pain needs."

https://www.sciencedaily.com/releases/2020/04/200408145805.htm

Center for Medicinal Cannabis Research Established at University of California

September 5, 2000

Science Daily/University of California, San Diego

A statewide, state-funded initiative to rigorously study the safety and efficacy of medicinal cannabis to treat certain diseases is being established at the University of California. The Center for Medicinal Cannabis Research (CMCR), headquartered at UCSD, will be a collaboration between UCSD and UCSF, two of the UC system's leading biomedical research campuses.

The CMCR will administer $3 million in first-year funding to support and coordinate scientific research at universities and research centers throughout California, assessing the use of cannabis as an alternative for treating specific medical conditions.

Funding of the CMCR is the result of SB847 (Vasconcellos), passed by the State Legislature and signed into law by Governor Gray Davis in October 1999. The legislation calls for a three-year program overseeing objective, high quality medical research that will "...enhance understanding of the efficacy and adverse effects of marijuana as a pharmacological agent," stressing that the project "should not be construed as encouraging or sanctioning the social or recreational use of marijuana."

Data from these studies will be used to develop guidelines for appropriate pharmaceutical use of medicinal cannabis. California voters approved such use in 1996, but exactly what role the substance should play in patient care, and how it should be administered as a pharmaceutical agent, is ambiguous because of the lack of definitive research, said Igor Grant, M.D., professor of psychiatry at UCSD and director of the CMCR. Grant is also executive vice chair of the department of psychiatry and director of UCSD's HIV Neurobehavioral Research Center.

Co-directors of the CMCR are Donald Abrams, M.D., professor of medicine at UCSF; and J. Hampton Atkinson, M.D., professor of psychiatry, and Andrew Mattison, Ph.D., associate clinical professor of psychiatry and family and preventive medicine, both of UCSD.

The CMCR plans to solicit applications this fall, to be reviewed by an independent Scientific Review Board of national experts. Funding will be awarded to support research focusing on diseases and conditions as defined in a report by the National Academy of Sciences/Institute of Medicine, and by a National Institutes of Health expert panel, according to Grant.

"The politics of medical marijuana are behind us as we begin the important work of researching the safety and efficacy of medical marijuana," said Senator John Vasconcellos (D-Santa Clara). "The National Institutes of Health and the Institute of Medicine of the National Academy of Sciences have independently called for further studies. Now, because of the vision of the Legislature, the Governor and the University of California, the issue of medical marijuana is properly in the hands of physicians and researchers."

The symptoms and conditions for which cannabis might be a useful treatment option include:

* Severe appetite suppression, weight loss and cachexia due to HIV infection and other medical conditions;

* Chronic pain resulting from certain types of injuries and diseases such as AIDS;

* Nausea associated with cancer and its treatment; and

* Severe muscle spasticity caused by diseases such as multiple sclerosis.

"This is an important opportunity to continue to evaluate the therapeutic potential of cannabis," said Abrams, a UCSF oncologist and AIDS expert who has just completed the first clinical trial of inhaled marijuana in patients with HIV infection. "The findings from our initial safety trial suggest that studies of the possible effectiveness of marijuana should be launched now. This state funding will allow that to happen quickly so that we may finally get some needed answers."

Support will be awarded on a competitive basis to those studies determined to be of the highest scientific quality, with studies anticipated to begin as early as January 2001. Most of the studies are anticipated to be patient trials, said Grant, though there is also interest in funding some basic research that has direct relevance to understanding safety, efficacy, and mechanisms of action of cannabis chemicals for the conditions in question.

The cannabis to be used in the studies will be obtained from the National Institute on Drug Abuse in accordance with procedures developed by the Public Health Service. Studies may also utilize alternative, non-smoked preparations of cannabis, as these become available through pharmaceutical research and are approved for clinical trials by the appropriate regulatory bodies.

In addition to the Scientific Review Board that will provide independent review of research proposals, the CMCR leadership is appointing an Advisory Board to provide input on how the CMCR can meet its objectives in the most scientifically sound, responsible and timely manner.

https://www.sciencedaily.com/releases/2000/09/000904122146.htm