Science Proves It Works for a Wide Range of Conditions

Almost every state in the US has legalized the medicinal use of marijuana in at least some form. And already in 2017, there’s been a remarkable development that should lead to greater acceptance of medical marijuana nationally. On January 12, the Health and Medicine division of the National Academies of Sciences, Engineering, and Medicine issued a report on the therapeutic use of cannabis (the term preferred by experts). To write their report, doctors from the Harvard T.H. Chan School of Public Health, Johns Hopkins University, Duke University Medical Center and other leading medical institutions reviewed and summarized the findings of more than 10,000 scientific studies on cannabis.

The studies show that cannabis has “therapeutic effects” on a variety of health conditions, including chronic pain, sleep disorders, anxiety, post-traumatic stress disorder, depression, chemotherapy-induced nausea and vomiting, epilepsy, the muscle spasms of multiple sclerosis, brain injury, ­Tourette’s syndrome and other conditions.

Bottom line: Medical cannabis is a science-supported, effective therapy for symptomatic relief in a wide range of health problems.

Here’s what you need to know about the medical benefits of cannabis and—if you decide to try it—how to take advantage of those benefits…


Researchers at St. Louis University School of Medicine in Missouri discovered that brain cells (neurons) have receptor sites for cannabinoids, the active compounds in cannabis. (There are more than 100 cannabinoids in cannabis, along with hundreds of other compounds.) In fact, they found that there are more receptors for cannabinoids than there are receptors for any other type of neurotransmitter—the chemicals that relay messages between neurons, activating functions in the brain and the rest of the body.

Scientists also soon found receptors for cannabinoids in the immune system, the peripheral nervous system (outside the brain and spinal cord) and the gut, spleen, liver, heart, kidneys, bones, blood vessels, endocrine glands and reproductive organs.

In subsequent years, they found that the body itself generates cannabinoid-like compounds called endocannabinoids.

Finally, they discovered an entire (and previously undetected) “­endocannabinoid system” that regulates many mind-body functions, including memory, mood, aspects of digestion and energy balance. Scientists have concluded that the endocannabinoid system helps regulate a huge number of mental and physical functions.

Medical cannabis works by triggering the endocannabinoid system, which is why its effects are so wide-ranging. What’s more, the endocannabinoid system employs a unique type of transmission called retrograde inhibition, which slows excessive activity in the body. With medical cannabis, there can be less pain, fewer muscle spasms, fewer seizures, less exaggerated tremors and less digestive upset.


The National Academies of Sciences report highlights many of the conditions helped by medical cannabis. Here is a sampling of the most recent research supporting some of the conclusions…

Chronic pain, including diabetic peripheral neuropathy and others. Many studies have shown that medical cannabis works for chronic pain. Example: Many people with diabetes suffer from chronic nerve pain in the feet and hands—symptoms include burning, electric shocklike tingling and dismaying numbness. Publishing their results in Journal of Pain, researchers from University of California, San Diego, found that medical cannabis could control nerve pain in people with diabetes.

Parkinson’s disease. Use of medical cannabis led to improvement in well-being and quality of life for people with Parkinson’s disease, according to a study published in Journal of Psychopharmacology.

Epilepsy. A study published in Lancet Neurology from researchers at major medical schools across the US found that medical cannabis reduced the frequency of seizures in patients with ­“severe, intractable…treatment-resistant epilepsy.”

Inflammatory bowel disease (Crohn’s). Israeli researchers at Meir Medical Center, publishing a study in Clinical Gastroenterology and Hepatology, found remarkable improvements in 21 Crohn’s patients who hadn’t responded to conventional medical treatment—five had “complete remission”…10 of the 11 had an average decrease in symptoms of 69%…and three were able to stop taking steroid drugs to control the disease. Many had improved appetite and slept better.

Multiple sclerosis. A study ­published in Journal of Neurology, Neurosurgery & Psychiatry found that cannabis extracts were twice as effective as a placebo in relieving muscle stiffness and pain in people with multiple sclerosis.


In some states where medical cannabis has been legalized, getting a doctor’s prescription for use of the medicine might be more or less automatic, just as it is with other sorts of medicines—you might spend a few minutes in the exam room and then be out the door with your prescription. But that is not necessarily a good thing.

You need to know how medical cannabis will work for your problem. You need to know the best dose for symptom control—one that controls your symptoms without a level of mental impairment that is uncomfortable or makes you ­dysfunctional. Starting with a low dose and slowly increasing the dose is the best approach—an approach that needs monitoring by your doctor and you.

Finding the best strain of cannabis to use for your health problem can be a matter of trial and error. Different cannabinoids have different effects. THC (tetrahydrocannabinol) is “psychoactive”—it creates euphoria (and is the reason that so many people use cannabis recreationally). Cannabidiol (CBD) is not psychoactive—it partially blocks some of the euphoria caused by THC. You and your doctor need to pick a strain and a dose that work best for you.

There also is the route of administration, which includes both vaping and smoking. Vaping requires the use of a vaporizer, which minimizes respiratory irritability—the plant matter is vaporized into gas rather than burned into smoke. This method is ideal for rapid relief in conditions such as severe, exacerbated chronic pain, migraines, nausea and vomiting, and asthma.

Another option is taking capsules of a cannabis extract such as Dronabinol. This is absorbed more slowly into the bloodstream and can provide three to six hours of therapeutic effect. For example, a dose that delivers five milligrams of THC works for patients who have trouble sleeping because of anxiety—it can provide three to six hours of good sleep if taken one hour before bedtime. There also are topical treatments. For example, topical tincture of cannabis can relieve muscle spasm or arthritic pain in the fingers and wrist.

To find a well-informed doctor, I recommend contacting the American Academy of Cannabinoid Medicine and asking for the name of a doctor near you who is a member of the academy (805-961-9988, Another organization that can help you find a doctor is Leafly (


As a physician who has worked with thousands of patients using medical marijuana, I can say that it is very safe—and not addictive.

In fact, cannabis creates fewer addictive symptoms than alcohol, nicotine and narcotic painkilling drugs. There is less risk for “dependency” than with any prescription pain or antianxiety medication. Little or no “tolerance” develops (tolerance is when you have to use more and more to achieve the same effect). There are few withdrawal symptoms, if any. All in all, cannabis is about as ­“addictive” as coffee.

There are possible side effects, however. The main one is coughing, which you can avoid by using a vaporizer or a noninhaled form. Another possible downside is dysphoria (feeling out of touch with reality, dissatisfied with life) or, on the other hand, excessive euphoria, which despite what you might expect can be an unpleasant side effect. Dysphoria or excessive euphoria are most likely when a new user takes a dose of THC that is too high. On the other hand, in patients with cancer or AIDS, a little euphoria to relieve anxiety and depression might be just what the patient needs—again, all of these possibilities can (and should) be worked out in your discussions with your doctor. Don’t be afraid of medical cannabis. There are a great many people whom it has and can help.