The opium poppy and marijuana have been used for millennia in traditional medicines for the relief of pain and serious illnesses. However, their potential for addiction and the social problems that they cause has led to government regulations that make the possession of these herbal products illegal. Morphine, which is generally 8 to 14 percent of the dry weight of opium, is a powerful analgesic that is used in modern hospitals to control pain for dying patients and for patients with serious injuries.
Marijuana, a variety of hemp plant, has had a more difficult transition into the modern medicine chest because it is often abused as a recreational drug. The active components of marijuana are called cannabinoids. Hashish is produced from Cannabis indica plants that are traditionally cultivated in India, Afghanistan, Bangladesh and Pakistan. Cannabidiol (CBD) is a main psychoactive component of hashish. Marijuana is produced from Cannabis sativa and its main active component is tetrahydrocannabinol (THC).
Medical cannabis has been documented as an effective treatment for nausea, vomiting, neurogenic pain, glaucoma, and many other conditions. Cannabidiol has also been found effective at stopping breast cancer from spreading throughout the body. Several states, like Colorado and Washington, have legalized the purchase and possession of marijuana, but it is still banned under the federal Controlled Substances Act.
Approximately 1100 metric tons of marijuana are smuggled each year from Mexico to supply the recreational drug market, and large quantities are also grown within the United States. Young people often believe that regular marijuana use is not harmful, and many high school age students use cannabis on a daily basis. A study at Duke University followed 1037 individuals from age 13, before initiation of cannabis use, to age 38. Neurophsychological testing found that persistent cannabis use was associated with a broad decline in cognitive function. Impairment was concentrated among adolescent-onset cannabis users, with more persistent use associated with greater decline. The changes were permanent. Cessation of cannabis use did not fully restore neuropsychological functioning among adolescent-onset cannabis users.
 Madeline H. Meier, et al., Persistent cannabis users show neuropsychological decline from childhood to midlife, PNAS, October 2, 2012, (109) 40, E2657–E2664, doi: 10.1073/pnas.1206820109