A new study from the Substance Abuse and Mental Health Services Administration (SAMHSA) finds that the prevalence of illicit drug use -- and drug preferences -- vary widely among the states.

The SAMHSA report, drawn from data gathered by the 2006 and 2007 National Surveys on Drug Use and Heath, found, for example, that use of drugs ranges from a low of 5.2 percent in Iowa to a high of 12.5 percent in Rhode Island. However, Iowa had one of the nation's highest rates of alcohol dependence.

"This report shows that while every state faces its own unique pattern of public health problems -- these problems confront every state," said SAMHSA acting administrator Eric Broderick. "By highlighting the exact nature and scope of the problems in each state we can help state public-health authorities better determine the most effective ways of addressing them."

Vermont led the nation in marijuana use, while Utah had the fewest marijuana users, the report said. Both rates were relatively low, however: 2.5 percent of Vermonters ages 12 and older reported marijuana use, compared to 1.6 percent of Utahns. Utah also had the lowest rate of underage drinking (17.3 percent), whereas 40 percent of North Carolina youth under age 21 reported drinking.

The report, which includes state-specific data on 23 measures of addiction and mental-health problems, is published on the SAMHSA website.