The review found that the past-year use of ‘any illicit drug,’ cannabis, cocaine, tranquilizers, and injecting drugs decreased between 2001 and 2004 in Australia, but remained stable for all these drugs except ecstasy between 2002 and 2004 in the United States. The use of hallucinogens decreased in both countries. Alcohol and use of many illicit drugs by teenage girls in both countries increased to rates similar to or higher than boys, and teens in both countries reported binge and heavy drinking in the past month. Australians in their 20s had the highest rates of use, but in the United States, past-year use of many drugs was highest among teenagers. The work notes that more treatment services are needed, particularly for people dependent upon non-opiate drugs. The changes in acceptability of use of different drugs and their perceived availability are related to changes in prevalence rates. Even with the similarities in levels of use, there are differences in patterns of use and preferences for certain drugs in each country, and geographic proximity to drug sources is a factor. Data were obtained from the 2004 Australian National Drug Strategy Survey, a multistage area probability sample, and the 2004 U.S. National Household Survey on Drug Abuse, also a multistage area probability sample. The U.S. survey data were recalculated to match age groups in the Australian data. Statistically significant changes were reported, and differences in prevalence of use by gender within age group were tested for significance. Tables, references