Although marijuana dependency is probably the least severe of the drug dependencies in terms of acuity and severity of negative consequences, it is one of the most difficult to treat. In this paper I propose that some of the difficulty in treating marijuana dependency in adolescence is due to the adolescent's impairment in recognizing the negative effects of regular use. This impairment in recognizing impairment is the result of the combination of both the executive function cognitive deficits and that everything is experienced in a mild high state. Adolescents then begin to lose the capacity to make meaningful logical connections between their drug usage and its effects on their life. Understanding this process helps the therapist to tolerate the frustrations in treating these adolescents. Suggested treatment interventions are to first establish an initial period of abstinence for 3-4 weeks. This can be done by utilizing one or more of the following: parental limit setting with random urine drug screens, contingency management techniques, direct suggestions to try abstinence for a limited time, and/or positive program peer pressure that abstinence is necessary to be part of the group. After a period of abstinence, the usual therapy approaches of motivational enhancement therapy, cognitive behavioral therapy, family therapy, community reinforcement approach, 12-Step mutual help programs and pharmacotherapy of co-morbid disorders may become more meaningful. Other practical clinical interventions with case examples are described.