Early and persistent use of marijuana has been associated with chronic bronchitis, increased risks of several cancers, attention and memory impairment, and significant reduction in IQ, as well as increased risk of serious mental illness. There is an association between early marijuana use and subsequent abuse of other illegal drugs and excessive alcohol consumption. Other recent research has demonstrated that marijuana use in adolescence has a negative impact on college degree attainment, adult income, and measures at age 25 of relationship and life satisfaction. In Vermont more adolescents are in treatment for marijuana disorders than any other substance including alcohol.

Region-specific prevention practices can be found in "Planning for Prevention-A Guide to Community Health Initiatives" through Northwest Regional Planning Commission.