After more than two decades of exhaustive scientific research, it is clear that drug courts significantly reduce drug use and crime at substantial cost savings. Five independent meta-analyses all report superior effects for drug courts over randomized or matched comparison samples of drug offenders who were on probation or undergoing traditional criminal case processing. In each analysis, the results revealed that drug courts significantly reduce rearrest or reconviction rates by an average of approximately 8 to 26 percent. A recent cost-related meta-analysis concluded that drug courts produce an average of $2.21 in direct benefits to the criminal justice system for every $1.00 invested. When drug courts targeted their services to the more serious, higher risk offenders, the average return on investment was determined to be even higher: $3.36 for every $1.00 invested. Drug courts have had the greatest effects on high-risk participants who were relatively younger, had more prior felony convictions, were diagnosed with antisocial personality disorder, or had previously failed in less intensive dispositions. The "key components" of the drug court model are hypothesized to include a multidisciplinary team approach, an ongoing schedule of judicial status hearings, weekly drug testing, contingent sanctions and incentives, and a standardized regimen of substance abuse treatment. Longer tenure in substance abuse treatment predicts better outcomes, and drug courts have been shown to retain offenders in treatment considerably longer than most other correctional programs. Significantly better outcomes have been achieved when drug courts adopted standardized, evidence-based treatments, including Moral Reconation therapy, the MATRIX Model, and Multi-Systemic therapy. These evidence-based treatments are similar in being highly structured, being clearly specified in a manual or workbook, applying behavioral or cognitive-behavioral interventions, and taking into account participants' ethnic cultures. 46 references