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Early Marijuana Use Linked to Adult Dependence


A new federal report released today concludes the younger children are when they first use marijuana, the more likely they are to use cocaine and heroin and become dependent on drugs as adults.

The report, "Initiation of Marijuana Use: Trends, Patterns and Implications," found that 62 percent of adults age 26 or older who initiated marijuana before they were 15 years old reported that they had used cocaine in their lifetime. More than 9 percent reported they had used heroin and 53.9 percent reported non-medical use of psychotherapeutics. This compares to a 0.6 percent rate of lifetime use of cocaine, a 0.1 percent rate of lifetime use of heroin and a 5.1 percent rate of lifetime non medical use of psychotherapeutics for those who never used marijuana. Increases in the likelihood of cocaine and heroin use and drug dependence are also apparent for those who initiate use of marijuana at any later age.

The report is based on the 1999 and 2000 National Household Surveys on Drug Abuse and was released today in Miami by Drug Czar John Walters and Charles G. Curie, Administrator of the Substance Abuse and Mental Health Services Administration (SAMHSA). SAMHSA is part of the U.S. Department of Health and Human Services (HHS).

The report found that 18 percent of people age 26 and older who began using marijuana before age 15, met the criteria for either dependence or abuse of alcohol or illicit drugs, compared to 2.1 percent of adults who never used marijuana. Among past year users of marijuana who had first used marijuana before age 15, 40 percent met the criteria for either dependence or abuse of alcohol or illicit drugs.

White House Office of National Drug Control Policy Director John Walters stated, "every day in this country, more than 3,000 people - most of them under the age of 18 - use marijuana for the first time. Their early marijuana use exposes them to risks of drug dependencies, long-term physical and cognitive consequences, and social problems. We must keep our young people out of harm's way by educating them on the dangers of marijuana use, preventing initiation of the drug, and getting them help if they have already starting using it."

Overall, the report found an estimated 2.0 million Americans aged 12 or older indicated they used marijuana for the first time in 1999. This was fewer than the 2.5 million new users in 1998, but still above the number, 1.4 million new users, found in 1989 and 1990.

SAMHSA Administrator Curie said, "among recent initiates of marijuana nearly three quarters had first used between the ages of 13 and 18. More than a quarter initiated before age 15. These findings are of grave concern because studies show smoking marijuana leads to changes in the

brain similar to those caused by cocaine, heroin and alcohol. Heavy

marijuana abuse impairs the ability of young people to retain information during their peak learning years when their brains are still developing."

Prior use of alcohol or cigarettes was highly correlated with becoming a new marijuana user. Among persons aged 12 to 25 who had never used marijuana, those who had smoked cigarettes were an estimated 6 times more likely than nonsmokers to initiate marijuana use within 1 year. Alcohol users were an estimated 7 to 9 times more likely than nonusers to start using marijuana within a year. Daily cigarette smoking was associated with a twofold increase in risk for marijuana initiation.

On average during 1998 and 1999 there were 3,197 male marijuana initiates and 2,989 female initiates per day. The average number of marijuana initiates per day during 1998 and 1999 was highest in June and July. For females, the months with the highest rates of initiation were January and July. Among males, the number of daily initiates increased to approximately 4,300 in June and July. Among females, the estimated initiates per day rose to 3,625 in July and 3,519 in January.

The average annual incidence rates varied across different States and age groups. Colorado, Delaware, Massachusetts, New Hampshire, and Vermont were ranked in the top 10 for the overall age group (ages 12 or older), the youth age group (ages 12 to 17), and the young adult age group (ages 18 to 25).

The 10 states with the highest overall rates of recent new marijuana users were Alaska, Colorado, Delaware, Massachusetts, Minnesota, New Hampshire, New Mexico, North Dakota, Vermont and Wisconsin. The nine states with the highest rates of recent new marijuana users aged 12-17 were Arizona, Colorado, Delaware, Hawaii,, Massachusetts, Nevada, New Hampshire, New Mexico and Vermont.

Several states were high in more than one age category. Colorado, Delaware, Massachusetts, New Hampshire and Vermont ranked in the top10 in three age categories, the overall age group (ages 12 or older), the youth age group (ages 12-17), and the young adult age group (ages 18-25). New Mexico ranked high for both the overall and youth age groups. Minnesota had a high rate for both the overall and young adult age groups.

States with the lowest overall rates of recent new marijuana users include Alabama, Arkansas, Florida, Indiana, Louisiana, New Jersey, New York, Pennsylvania, Virginia and West Virginia. The lowest rates of recent marijuana initiates aged 12 to 17 were in Alabama, the District of Columbia, Idaho, Louisiana, Mississippi, New Jersey, Pennsylvania, Texas, Utah and Virginia.

Louisiana had a low rate in three categories, recent new users for the overall rate of new marijuana users, youth and young adult age groups. Texas and Utah had a low rate in two categories, recent initiation among youth, and young adults.

SAMHSA, a public health agency within the U.S. Department of Health and Human Services, is the lead federal agency for improving the quality and availability of substance abuse prevention, addiction treatment and mental health services in the United States. Information on SAMHSA's programs is available on the Internet at


News from the Substance Abuse & Mental Health Services Administration

Press Contact: Leah Young Phone: (301) 443-8956

The Substance Abuse and Mental Health Services Administration (, an agency of the U.S. Department of Health and Human Services.