Marijuana has many uses: getting high, making rope, and looking cool, among others. But there’s one particular use that has kept pot popular for centuries, if not millennia.
As a medicine, cannabis may just be a wonder plant. It treats a wide range of conditions, from nausea and muscle spasms to anxiety and insomnia. It may be the best medical options available for many patients.
There’s nothing new about the medicinal use of marijuana, but the modern era didn’t really start until 1996: That’s when California voters passed the first medicinal cannabis law. Several other states followed suit, and by 2016, there were 42 states that allow some form of MMJ.
Which Chemicals in Cannabis Treat Disease?
Marijuana contains a host of important chemicals known as cannabinoids. These substances mimic similar cannabinoids produced by the human body, and they influence a wide range of mental and physical processes, including appetite, pain sensitivity, and mood. The most critical chemicals found in cannabis are THC and CBD.
THC. THC, or tetrahydrocannabinol, is the cannabinoid that gets marijuana users high. The more THC a sample of cannabis contains, the more intoxicating it is likely to be for the people who smoke it. This is the chemical most sought after by recreational users, but it also serves many medical purposes.
CBD. CBD, by comparison, is non-intoxicating, but also has a wide range of medicinal uses. Formally known as cannabidiol, CBD is used primarily to treat children with intractable seizure disorders, but it can also help with multiple sclerosis, cancer, and other conditions. This cannabinoid is especially popular in deep red states, where it can be used as medicine without causing the high that motivates many conservatives to oppose marijuana reform.
Which Conditions Does Medical Cannabis Treat?
So what is cannabis good for as a medication? Here are just some of its many uses.
The data on anorexia and marijuana remains somewhat scarce, but the drug is well known to increase hunger in many of its users. Anorexia nervosa involves pathological weight loss driven by psychological problems. It’s unclear whether cannabis can relieve those underlying problems, but its effect on appetite could spur some anorexics to eat more.
Marijuana can be used to treat the chronic pain and inflammation associated with rheumatoid arthritis, osteoarthritis, and psoriatic arthritis, as well as other conditions involving arthritic joints.
Cachexia is a form of chronic wasting caused by cancer, its treatments, and a number of other medical problems. Cannabis can effectively boost appetite, allowing patients with this condition to reach and maintain a healthy weight.
Marijuana is also used to treat cancer on two fronts. First, it alleviates the nausea, vomiting and pain caused by chemotherapy and radiation treatment. Second, it may actually fight cancer cells, preventing and even shrinking tumors.
Crohn’s Disease is a chronic inflammatory bowel disease that causes discomfort, pain, and digestive problems. The ulcers and pain associated with this gastrointestinal disorder condition can be disabling, but marijuana has shown great promise in relieving the worst of the symptoms.
Researchers have established that marijuana is effective in improving appetite, fighting insomnia, and even sending Crohn’s into remission.
A growing body of science shows that marijuana is effective in alleviating chronic pain, though these conclusions remain controversial. This is the most common reason patients seek medical cannabis. States have been slow to add chronic pain to their lists of qualifying conditions, but the science behind pot as a painkiller is growing stronger.
Marijuana may also be helpful in treating and even preventing Alzheimer’s disease and other types of dementia. Scientists believe Alzheimer’s is caused by cellular inflammation in the brain. Weed, which is an effective anti-inflammatory, may ward off that inflammation and help prevent dementia.
Diabetics can benefit from medical cannabis, as well. Regular use of the drug leads to lower insulin levels, lower insulin resistance, and slimmer waistlines, all good news for patients who have Type 2 diabetes or are at risk of developing it.
In the United States, marijuana was first used primarily to treat glaucoma, a condition that involves excessive blood pressure in the eyes. Cannabis reduces that pressure and helps prevent further damage to the retina. Cannabis was also recommended for nausea by at least as early as the 1970s.
Cannabis is used to treat a host of symptoms caused by HIV and AIDS, including loss of appetite, cachexia or wasting syndrome, pain, and nausea, as well as depression and other emotional issues.
HIV is much more survivable than it used to be. In the early years of the AIDS crisis, a diagnosis was a death sentence. Now, patients routinely live full lives on a complex regimen of medications, including cannabis.
Migraine headaches, a common and sometimes debilitating condition, can be treated with marijuana, which is used primarily to relieve the intense pain that accompanies them.
MS is a progressive, neurodegenerative disease, and though there is no cure, cannabis is one of several medications that can make a critical difference in reducing symptoms. The drug helps ease the pain and muscle spasms that define the disorder, and is covered by MMJ in most states that allow the drug.
One of the first medical uses of marijuana was as a treatment for the severe nausea caused by cancer and its treatments. It can also effectively relieve other forms of nausea, including those caused by AIDS and chronic digestive disorders.
Much of the recent attention to medical marijuana has focused on its success in treating severe epilepsy. Cannabidiol (or CBD), one of the constituent chemicals of cannabis, effectively reduces brain activity that causes convulsions, especially in children. This discovery has greatly increased support for medical pot laws.
Several mental illnesses are thought to respond to MMJ, including anxiety, mood disorders, and obsessive-compulsive disorder. But the drug is particularly helpful in treating Tourette’s syndrome, a neuropsychiatric disease typified by physical tics and obsessive-compulsive behaviors. Repeated studes have shown weed can reduce these symptoms without serious adverse effects.
The data on mental illness is still a little unsettled, but many sources suggest pot can reduce the symptoms of anxiety, mood disorders, and ADHD. Evidence is limited on this front, with some suggesting cannabis may actually harm some patients with serious mental illnesses.
States with Medical Marijuana
As of 2016, 48 states and the District of Columbia allow some form of medical marijuana. California was the first to legalize medicinal cannabis, with the Compassionate Use Act of 1996.
A majority of these states allow so-called “whole-plant” medical marijuana, which can include noticeable levels of the intoxicating chemical THC. The others restrict medicinal use to plant matter containing only CBD, a non-intoxicating chemical used to treat seizures and a short list of other conditions.
The states which allow whole-plant medicinal cannabis, including THC, are shown in the table below, along with the associated possession limits.
1 oz usable; 6 plants (3 mature, 3 immature)
2.5 oz usable; 12 plants
3 oz usable per 14-day period
8 oz usable; 6 mature or 12 immature plants
2 oz usable; 6 plants (3 mature, 3 immature)
2.5 oz usable
6 oz usable
Amount to be determined
4 oz usable; 10 plants
2.5 ounces of usable cannabis during a period of 14 days
2.5 oz usable; 6 plants
30-day supply, amount to be determined
60-day supply for personal medical use (10 oz)
2.5 oz usable; 12 plants
30-day supply of non-smokable marijuana
1 oz usable; 4 plants (mature); 12 seedlings
2.5 oz usable; 12 plants
Two ounces of usable cannabis during a 10-day period
2 oz usable
6 oz usable; 16 plants (4 mature, 12 immature)
30-day supply non-smokable marijuana
3 oz per 14-day period
Maximum of a 90-day supply, amount to be determined
3 oz usable; 12 plants (6 mature, 6 immature)
24 oz usable; 24 plants (6 mature, 18 immature)
2.5 oz usable; 12 plants
2 oz usable; 9 plants (2 mature, 7 immature)
8 oz usable; 6 plants
2 oz dried
30-day supply (amount TBD)
At least three states with whole-plant MMJ – Minnesota, New York, and Pennsylvania – ban the smoking of marijuana. Patients must vaporize the drug, eat it in the form of edibles, or use another form of delivery, such as a transdermal patch or tincture.
Cultivating Cannabis as Medicine
At least 20 states allow cultivation of marijuana as medicine, including the nine where the drug is legal for any use. The District of Columbia also allows home grows for medical use. But these laws often change due to court rulings and new legislation, so public information about them may not be up to date.
As a general rule, states with whole-plant marijuana allow medical grows, while those with CBD-only laws do not. A few states have decriminalized small gardens without legalizing medicinal marijuana. Uniquely, Washington allows cultivation for medicine but not recreation.
How to Become a Medical Marijuana Patient
Each state has its own process for becoming a medical marijuana patient. Some require formal registration with health officials, while others (most notably California) mandate only a piece of paper from a doctor.
But these “recommendations” are the most important step in any state that allows the sale or cultivation of medicinal cannabis. They stand in for formal prescriptions, as the FDA regulates prescribing practices and marijuana is prohibited by federal law.
To get a recommendation, a patient must first demonstrate that he or she has a legitimate medical condition that qualifies him or her for medicinal pot. This usually involves a full exam by a physician, but the rules are tighter in some places than in others.
In some places it may be necessary to obtain a medical marijuana card in order to buy the drug. These cards also prove useful when interacting with police, but not every state requires them.
Historic Medical Use of Marijuana
Archaeologists said the Siberian woman apparently used cannabis to treat the breast cancer that ultimately killed her. Her altered mental states may even have made her a revered figure in her society.
The ancient Chinese also understood the medical benefits of marijuana. Nearly 3,000 years before the birth of Christ, Emperor Neng became the first MMJ patient in recorded history.
Many centuries later, another famous figure, Queen Victoria of Great Britain, openly used medical marijuana to treat her severe menstrual cramps. Along with other world leaders, including Napoleon, the queen helped make the drug more popular and widespread.