A new study shows that nearly 9% of the American population use illegal drugs, including abuse of prescription drugs and regular use of marijuana, cocaine, heroin, hallucinogens or inhalants. According to the 2010 National Survey on Drug Use and Health, marijuana was the most popular drug.

There are 17.4 million regular users — amounting to 6.9 percent of the population compared to 5.8 percent in 2007. USNews.com reported that nearly half of kids between 12 and 17 claimed it would be €œfairly easy€ or €œvery easy€ to acquire marijuana, according to the survey.

In a statement, the US director of national drug control policy, Gil Kerlikowske, called the survey result a sign of €œunacceptable levels€ in the US. Around 7 million people abused psychotherapeutic drugs (including painkillers and sedatives) last year while 1.2 million used hallucinogens. These levels have been steady in the last few years.

The study was not all bad news. As in previous years, 1.5 million use cocaine but it′s a drop of nearly a million since 2006. Other hard drugs such as Methamphetamine have also  seen a drop in regular users.

What is worrying researcher is the growth in young users — the number of 18 to 25-year-olds who use drug have risen from 19.6% in 2008 to 21.5% in the 2010 survey. The hike is considered to be linked to increased marijuana use and Kerlikowske says to CNN that states who allow medical marijuana could be fueling this development.

€œEmerging research reveals potential links between state laws permitting access to smoked medical marijuana and higher rates of marijuana use,€ reports CNN. Kerlikowske continues: €œI urge every family – but particularly those in states targeted by pro-drug political campaigns – to redouble their efforts to shield young people from serious harm by educating them about the real health and safety consequences caused by illegal drug use.€

Parental control could however prove difficult, as USNews.com reveals how surveyed parents fared pretty bad when it came to guessing their children′s use of drugs or alcohol. In the anonymous survey, 9.5% of parents said their teenagers smoked marijuana while 17% of the teens admitted to their use.