Cannabis has been used to treat ailments for at least 3,000 years.
Nevertheless, the Food and Drug Administration has not approved cannabis for the treatment of any medical condition, although cannabidiol, a substance present in cannabis, was approved in June 2018 as a treatment for certain types of epilepsy.
Recent efforts toward legalization have further exacerbated this tension between widespread belief that cannabis treats a variety of ailments and little scientific understanding of its effects. Some studies suggest that cannabis may be of benefit in treating conditions such as chronic pain, alcoholism, drug addiction, depression, anxiety, cancer, epilepsy, and multiple sclerosis. At the other end of the spectrum is the plethora of studies that have found negative associations between cannabis use and health such as mental health problems, testicular cancer, and respiratory disease. There is evidence that demonstrates both the harms and health benefits of cannabis. However, despite recent comprehensive reviews of scientific studies evaluating the benefits and harms of cannabis, more research is needed to determine the full public health implications of increased cannabis use. The Drug Enforcement Administration classifies cannabis as a Schedule I controlled substance, which discourages researchers in this area from studying cannabis and cannabinoids. Whenever you use cannabis for medical reasons, you and your doctor should carefully consider how these factors relate to your illness and health history. There is some evidence to support the use of cannabis for pain relief, but you should avoid it if you have a history of mental illness.