The admission rate for those who seek treatment for marijuana use nearly tripled between 1992 and 2002, according to the latest data compiled by the federal government.
The numbers released Friday reflect a growing use of marijuana in the 1990s and an increase in the potency of marijuana, said Tom Riley, a spokesman for the White House's Office of National Drug Control Policy.
"This report makes clear what people in the public health community have known for years, which is marijuana is a much more dangerous drug than many Americans realize," Riley said. "This report is a wake-up call for parents that marijuana is not a soft drug. It's a much bigger part of the addiction problem than is generally understood."
The study on treatment rates was conducted by the Substance Abuse and Mental Health Services Administration, which estimated that 41 states experienced an increase in the number of people who sought treatment for marijuana use during the decade studied.
Overall, the admission rates rose from 45 per 100,000 people in 1992 to 118 per 100,000 people in 2002, which is the latest year such numbers are available.
"Marijuana is not a harmless substance, and these treatment trends emphasize that point," said Charlie Cook, the administrator for the Substance Abuse and Mental Health Services Administration.
By Kevin Freking