NEW YORK – There’s some very good news in the battle against illicit drugs: Use by America’s teens has dropped more than 23 percent during the last five years. But their abuse of medicines, both over-the-counter and prescription, is rising. These opposing trends – detailed in a survey of teens released Thursday – reflect the complexity of the US drug scene. They also present a new set of challenges. The most important: How to apply the prevention tools that have apparently succeeded in combating illegal drug use to fight the abuse of legal medicines. Experts credit campaigns focusing on parental involvement and the dangers of abuse for the significant declines in not only drugs like marijuana, but alcohol and cigarettes as well. The newly released Monitoring the Future study, which experts consider to be one of the most definitive in the US, is done by the University of Michigan and funded by the National Institute on Drug Abuse. It found that teen use of marijuana – their most common drug – declined from 35 percent in 2001 to 29 percent in 2006. ‘The broad nature of these declines across multiple drugs and alcohol and cigarettes … […]