Cannabidiol is a cannabinoid and a major component of the cannabis plant, or marijuana plant. By itself, it lacks the psychoactive effects most commonly associated with marijuana use yet still retains many of the medicinal benefits, such as its anti-seizure and anti-inflammatory effects. The legal status of this substance varies from country to country. In the United States, for instance, it and all other phytocannabinoids are classified as Schedule I controlled substances, making possession or ingestion illegal.
There are a number of medical uses for cannabidiol. Extracts act as a potent pain reducer and have been used to treat the chronic pain associated with multiple sclerosis and arthritis. It also functions to reduce the likelihood and severity of seizures, so it has been used as a treatment for epilepsy as well. Studies have shown that this substance might be an effective treatment for the symptoms of the neurological movement disorder dystonia.
Advocates for the use of cannabidiol for medicinal purposes, either when smoked in marijuana or when ingested in extract form, often draw attention to the low occurrence of side effects compared with other available treatments. Additionally, many traditional prescription drugs that are used to treat pain, for instance, have a very high risk of forming chemical dependencies in the user. The cannabidiol found in marijuana has been found to effectively reduce pain levels without these high risks. Detractors note that because it can be found only in an illegal drug, any positive effects are largely irrelevant.
The amount of cannabidiol found in a particular marijuana plant can vary greatly. Marijuana intended for illegal drug use is usually much higher in tetrahydrocannibinol (THC), the main psychoactive component of marijuana that acts to induce a high. Cannabis plants intended for use as hemp, on the other hand, contain a much higher concentration of cannabidiol and only trace amounts of THC. Medical marijuana, while still containing high amounts of THC, can contain as much as 40 percent cannabidiol in extracts.
It has been shown that this substance also serves to directly counteract the anxiety-inducing effects of THC. This means that a strain of marijuana that is high in THC but low in cannabidiol is more likely to induce anxiety and schizophrenia-like symptoms in a user. A strain with higher amounts of cannabidiol, such as those most often associated with medical marijuana, is less likely to produce these symptoms.