More than half of Americans aged 12 and up drink alcohol, a quarter binge-drank in the past month, and one in 14 teens has used marijuana, a US government agency says in a report on substance abuse.
Around 52 percent of 137,436 Americans interviewed in 2008 and 2009 said they had a tipple in the past month, the report released late last month by the Substance Abuse and Mental Health Services Administration (SAMHSA) says.
Drinking was most prevalent among 18-25 year olds, with the northeastern state of New Hampshire leading the charge: three-quarters of young adults in the state said they'd used alcohol in the past month, the report says.
The legal drinking age in all 50 states is 21, although exceptions in many states allow under-age drinking in certain circumstances, such as in private premises with parental consent.
SAMHSA also found that almost a quarter (23.5 percent) of Americans binge-drank in the past month -- defined as having four or more drinks for women or girls and five or more for men or boys.
In North Dakota, nearly one in three residents and more than a quarter of young people aged 12-20 binge-drank, the highest rates in the United States.
In the US taken as a whole, under-age binge drinking was down from 19.2 percent in 2002-2003 to 17.7 percent in 2008-2009, the report says.
SAMHSA also looked at Americans' marijuana use and found that numbers using pot in the past month were up for the two years covered by the report: 6.4 percent of Americans aged 12 and older said they had used marijuana in the past month compared to six percent in 2007-2008.
In the 12- to 17-year age group, marijuana use fell, but seven percent of US teens still use cannabis, the report said.
The 10 states that saw the highest use of marijuana were Alaska, Colorado, the District of Columbia, Hawaii, Maine, Massachusetts, New Hampshire, Oregon, Rhode Island, and Vermont.
Medical marijuana is legal in all of those states except for Massachusetts and New Hampshire.
Perceptions of the dangers associated with marijuana use were lowest in the 10 states where the drug was used the most, according to the study.
Nearly a quarter (23.6 percent) of Americans aged 12 and older had smoked cigarettes in the past month, the study also found. At the same time, the number of Americans who perceived cigarette smoking as dangerous fell from just over 69 percent in 2007-2008 to 67.7 percent in 2008-09.
One in five American adults reported having some form of mental illness in the past year, and around one in 16 adults and one in 12 teens suffered depression in the past year, the study says.
The rates for mental illness and depression were unchanged from previous years, says the report, which is based on the 2008 and 2009 National Surveys on Drug Use and Health (NSDUHs).