Q: Is marijuana addictive?

A: "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." [p. 98]

Q: Does marijuana lead to harder drugs?

A: "It does not appear to be a gateway drug to the extent that it is the cause or even that it is the most significant predictor of serious drug abuse; that is, care must be taken not to attribute cause to association." [p. 101]

"There is no evidence that marijuana serves as a stepping stone on the basis of its particular physiological effect." [p. 99]

Q: Is marijuana more dangerous than tobacco?

A: "Given a cigarette of comparable weight, as much as four times the amount of tar can be deposited in the lungs of marijuana smokers as in the lungs of tobacco smokers. ... However, a marijuana cigarette smoked recreationally typically is not packed as tightly as a tobacco cigarette, and the smokable substance is about half that in a tobacco cigarette. In addition, tobacco smokers generally smoke considerably more cigarettes per day than do marijuana smokers." [Pp. 111, 112]

Q: Does marijuana cause other life-threatening health problems?

A: "Epidemiological data indicate that in the general population marijuana use is not associated with increased mortality." [p. 109]