According to the National Institute on Drug Abuse, people are considered addicted to marijuana if they continue to use even when it interferes with many aspects of their lives and if they have withdrawal symptoms when they try to quit. For those users who began using marijuana in their teens, the percentage of those who become dependent goes to about 17%. For those who smoke marijuana daily, the number who become dependent ranges from 25% to 50%. Additionally, a study of identical twins found that if one twin used marijuana before age 17, that twin was more likely to use other drugs and develop substance abuse problems later on, compared with their twin who did not start smoking pot early. NIDA surveys also show that:

In 2010, of the 7.1 million Americans abusing drugs, 4.5 million used marijuana.In 2009, approximately 18% of those seeking treatment for drug abuse reported marijuana as their primary drug.Also in 2009, 61% of persons receiving treatment under age 15 reported marijuana as their primary drug of abuse.

Other studies have found that some people experience withdrawal symptoms similar to those associated with nicotine withdrawal, when they quit smoking marijuana. Those symptoms included sleeping difficulties, craving for the drug, anxiety, and irritability.

Signs of Addictive Behavior

In general, here are some common signs and symptoms that someone has developed an addiction:

Developed a tolerance for the substanceTake more to avoid withdrawal symptomsUsed when you said you were not going toLife begins to revolve around the drug and seeking itAbandoned other activities you once enjoyedContinued to use in spite of problems it has caused