Major findings from this report regarding illicit drug use in Missouri indicate that marijuana is one of the most abused drugs in the State, accounting for 23.6 percent of all illicit drug mentions in 2008; that it is the greatest contributing factor for persons seeking treatment for illicit drug abuse and dependency; and that it is the drug of choice for the State's youth. Methamphetamine and amphetamines are the fourth most mentioned drugs during hospital admissions for illicit drug use, and are used disproportionately more by the State's White, adult population. The findings also indicate that heroin and opiates are a serious problem in Missouri, accounting for 43.1 percent of all illicit drugs diagnosed in the State in 2008. This report presents information on the current level of illicit drug use in the State of Missouri, examines the societal impact of drug use on State resources, and looks at the extent of drug industries in the State. Data for this report were obtained from several sources including the Missouri Department of Mental Health, the Missouri State Highway Patrol, Uniform Crime Report arrest data, the Multi-jurisdictional Drug Task Force Quarterly Report Information System, and two statewide surveys examining the extent of drug use in the State. Additional findings in the report indicate that the level of illicit drug use in Missouri has a significant impact on the resources and efforts used to control and treat the problem in the State. The report also contains a detailed analysis of the nature and extent of drug industries in the State from the cultivation and production of illicit drugs to their distribution and sale. Tables, figures, appendix, and references