For a comparison of the addictive qualities of various drugs, see www.drugwarfacts.org/addictiv.htm
"In summary, although few marijuana users develop dependence, some do. But they appear to be less likely to do so than users of other drugs (including alcohol and nicotine), and marijuana dependence appears to be less severe than dependence on other drugs." [IOM]
"A distinctive marijuana and THC withdrawal syndrome has been identified, but it is mild and subtle compared with the profound physical syndrome of alcohol or heroin withdrawal." [IOM]
"Compared to most other drugs, dependence among marijuana users is relatively rare." [IOM]
 The Substance Abuse and Mental Health Services Agency's own web site says "By 1999, more than half of all adolescent marijuana admissions were referred through the criminal justice system. Adolescent marijuana admissions through the criminal justice system increased at a higher rate than admissions through other sources."
"Researchers followed up on 25 male patients aged 16 to 28 who were strongly addicted to crack. Most of the subjects (68%, or 17 individuals) ceased to use crack and reported that the use of cannabis had reduced their craving symptoms, and produced subjective and concrete changes in their behavior, helping them to overcome crack addiction."
-Therapeutic use of cannabis by crack addicts in Brazil ; Labigalini, Rodrigues and Da Silveira. (Journal of Psychoactive Drugs, Oct-Dec 1999 )
Also: M. Dreher, 2002. "Crack heads and roots daughters: The therapeutic use of cannabis in Jamaica." Journal of Cannabis Therapeutics 2 (3-4):121-133
See: Gate Stopper