Marijuana, also known as cannabis, is made from hemp plants. It has a distinct smell and people use it in many ways. For example, some people smoke it as a joint, blunt, or through a pipe. Other people ingest marijuana through food or tea.¹

Though many people who use marijuana do not develop a problem, some people do. 35% of marijuana users showed dependence on the drug in some way like tolerance, withdrawal, and loss of control; fifteen percent of those users experienced tolerance.²

There are two types of dependence: Physical dependence and Psychological dependence.

Physical dependence occurs when the body needs a particular substance to function normally; this type of dependence often results in a person being physically ill when s/he stops using. Though physical dependence on marijuana can occur, it is very rare.³

Psychological dependence occurs when a person believes s/he needs a particular substance to function “normally.” The person might not be able to stop thinking about, or using, marijuana. Psychological dependence can be as powerful, or more powerful as physical dependence.

Signs of dependence:

Tolerance means a person is able to use larger amounts of a substance without experiencing the negative effects inexperienced users often feel.⁴ Tolerance of both physical and psychological effects can develop quickly.

Withdrawal occurs when a user experiences unpleasant, sometimes dangerous, effects after abruptly ceasing chronic use of a particular substance.⁵ Withdrawal symptoms for marijuana are usually not dangerous. Withdrawal symptoms often include cravings, anxiety, chills, depression, headaches, insomnia, irritability, nausea, restlessness, sleep disturbances, and tremors. Such symptoms of marijuana withdrawal usually last several days and up to several weeks.^{4, 3, 6}

Contemporary uses of medical marijuana are still debated. Some think that marijuana can lessen some health-related problems. For example, some suggest that marijuana reduces nausea, and as a result, many consider it a viable treatment for cancer patients undergoing chemotherapy. Similarly, marijuana potentially decreases pressure in the eye, and is therefore sometimes used to treat glaucoma. Finally, since marijuana is also known to increase appetite, it has been used to treat patients who have difficulty eating, such as those suffering from HIV/AIDS or anorexia nervosa.^{7, 8}

The United States federal government currently is against legalizing marijuana; the Supreme Court ruled in favor of the government in the prosecution of doctors who prescribe marijuana. ⁹ Federal and state laws occasionally conflict over the legalization of marijuana. Some states hold that it is legal to use marijuana for medicinal purposes (with a doctor’s recommendation only); including, Alaska, California, Colorado, Hawaii, Maine, Montana, Nevada, Oregon, Rhode Island, Vermont, and Washington.

Marijuana is the most commonly used illicit drug in the United States; as a result, those who try harder drugs have usually already tried marijuana ^{10, 11, 12}. Although it is a risk factor, most studies on this topic cannot establish a causal relationship between marijuana use and harder drugs.

People who use marijuana often participate in other risky behaviors, but research cannot say whether or not marijuana use causes such behavior. According to the U.S. Centers for Disease Control and Prevention, adolescents who use marijuana are more likely to have unsafe sex. Teen marijuana smokers are also twice as likely as their non-using peers to attempt suicide and carry a weapon.¹¹