4 Groundbreaking Studies on Cannabis and Disease

Written by Bonni Goldstein, M.D.

To date, 29 states and the District of Columbia have passed regulations allowing physicians to recommend medical cannabis to their patients. While anecdotal evidence supports the therapeutic value of medical cannabis, physicians have struggled to recommend specific dosages and treatment strategies as a result of insufficient clinical data.

Fortunately, research institutions around the world are investigating properties of cannabis for a variety of medical treatments. From the Children’s Hospital in Denver to Jerusalem’s Hebrew University, researchers are making significant strides toward uncovering the science behind cannabis. Scientists hope to answer patients’ questions such as, “How much cannabis do I need? In what form? How do I take it?”

Currently, four clinical trials are ongoing in North America. These trials are assessing the clinical benefits of cannabis for conditions such as post-traumatic stress disorder, Alzheimer’s disease, Parkinson’s disease and pediatric brain tumors.

1. Dr. Sue Sisley’s PTSD Study

Since May 2016, Dr. Sue Sisley and her team with the California-based Multidisciplinary Association for Psychedelic Studies have been preparing a study of four different potencies of smoked cannabis on treatment-resistant post-traumatic stress disorder (PTSD). Over the course of nine months, Dr. Sisley’s research team will observe 76 veterans diagnosed with chronic, intractable PTSD.

Each veteran will be randomly assigned to receive one of four types of cannabis with varying percentages of THC and CBD content as well as a placebo, fiber-variety “hemp” cannabis. Each participant will smoke two of the four types over a three-week period—up to 1.8 grams per day. Participants can use as much or as little as they need, and between each session, they will go through a two-week “wash” period where no cannabis use will be permitted. Throughout the study, the research team will observe changes in PTSD symptom severity and will rely on a friend or family member to report on the health and well-being of the participants.

This study will allow researchers to better understand the potential risks and benefits of cannabis use among veterans with PTSD and aid in cannabis-based decision making among patients and their physicians.

2. Alzheimer’s Induced Agitation

An important ongoing investigation underway in Toronto, Canada, is the Sunnybrook Health Sciences Centre’s study of nabilone, a synthetic compound with properties similar to THC, and its potential safety and efficacy in Alzheimer’s disease (AD). Starting in 2015, the study recruited 40 participants for 14 weeks of testing. Half the participants started with nabilone treatment for six weeks and will switch to a placebo at the midpoint. The other half of the participants started with the placebo and will switch to the nabilone at the midpoint. Both groups will take a one week break off the medication or placebo at the midpoint.  Researchers will be observing effects of nabilone on agitation as well as other neuropsychiatric symptoms: cognition, pain, inflammation, as well as vital signs.

Agitation, weight loss, and pain associated with AD creates a significant decline in quality of life. While antipsychotics are well-studied and often recommended, they are modestly effective and present potentially severe side effects. Nabilone has shown beneficial results in other studies and researchers hypothesize it may be effective for symptoms of this condition. Although nabilone is a single molecule compound (compared to the many compounds in the cannabis flower), results from studies such as this may provide insight into how THC may benefit Alzheimer’s patients.

3. CBD Toleration and Effects on Tremor in Parkinson’s Disease

The Colorado Department of Public Health tasked the University of Colorado with studying the tolerability and effects of cannabidiol (CBD) on tremors associated with Parkinson’s disease (PD). Individuals with PD have self-medicated with cannabis since it became medically legal in Colorado, yet no studies show whether it’s efficient in treating symptoms. Animal studies using CBD suggest that it reduces anxiety, decreases psychotic symptoms and improves both motor and non-motor symptoms in PD.

This study will first determine a tolerable dose of CBD in 10 patients with PD and measure changes in vital signs or negative effects as doses increase from a baseline level to 20 mg of CBD.  Subsequently, the effects of CBD on cognition, anxiety, sleep, fatigue, mood, pain, motor and non-motor PD signs will be measured.

Most current therapies of PD are minimally effective and poorly tolerated.  This detailed study is a step forward in examining the benefits and risks of CBD at specific dosages, providing much-needed information to physicians treating PD patients with cannabinoid medicine.

4. Medical Cannabis in Pediatric Central Nervous System Tumor Population

The University of Colorado is also conducting an additional, observational study in partnership with the Children’s Hospital Colorado Center for Cancer and Blood Disorders. Over the course of a year, the team will observe 150 children between ages 2-18 that are diagnosed with Central Nervous System (CNS) tumors, who are self-medicating with cannabis while receiving treatment at CHCO.

During this study, the research team will administer questionnaires and use diaries to gather data on medical cannabis use, delivery methods, what strains are used, frequency and dosing amounts, and the financial impact on families. While controversial due to its involvement of minors and lax observation methods, this novel study will provide unprecedented statistical insight into how children with CNS tumors and their families use medical cannabis treatment. The results may provide helpful information that will influence the use of medical cannabis in other cancer patients.

While there is evidence of the benefits of medical cannabis, these new studies are helping researchers and physicians find exact dosages and application methods for specific ailments. The prohibition of research has been an obstacle for physicians, scientists and patients alike. As opportunities for research opens up, and as clinical data and continued anecdotal evidence accumulates, the knowledge gained from these studies will help patients struggling with serious medical conditions to make informed decisions about using cannabis as medicine.

Bonni Goldstein, M.D. is a Los Angeles-based physician and medical advisor for Weedmaps, the world’s first and largest cannabis technology company, where users can search for medicinal cannabis products. Dr. Goldstein has successfully treated thousands of adult and pediatric patients with cannabis, and has recently been recognized as the 2017 Medical Professional of the Year by Americans for Safe Access (ASA).


Fred Campbell
Fred Campbell10 hours ago

Interesting. Lets hope for positive results and be able to determine appropriate dosages.

Angelika Kempter

Thank you for sharing

Leanne K
Leanne K2 days ago

I just KNEW there would be reference to animal testing! Must we reference such cruel and dodgy studies??? And of all things pot!

Marija Mohoric
Marija M2 days ago

tks for sharing

Danuta W
Danuta W2 days ago

thank you for posting

joan silaco
joan silaco1 months ago


W. C
W. C2 months ago

Thank you.

Sue M
Sue M2 months ago

Interesting - thanks

William C
William C2 months ago

Thank you.

Patricia D
Patricia D2 months ago

Thanks for the article.