We know that marijuana use, particularly long-term, chronic use or use starting at a young age, can lead to dependence and addiction. Long-term marijuana use can lead to compulsive drug seeking and abuse despite the known harmful effects upon functioning in the context of family, school, work, and recreational activities.
Research finds that approximately 9 percent (1 in 11) of marijuana users become dependent. Research also indicates that the earlier young people start using marijuana, the more likely they are to become dependent on marijuana or other drugs later in life.
In 2010, approximately 4.5 million people met the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) diagnostic criteria for marijuana abuse or dependence. This is more than pain relievers, cocaine, tranquilizers, hallucinogens, and heroin…combined. In 2010, over one million Americans aged 12 or older reported receiving treatment for marijuana use, more than any other illicit drug. http://oas.samhsa.gov/NSDUH/2k10NSDUH/2k10Results.htm#Fig7-8