(Baby Boomers) "In 2007, the rate of past year use in this age group [persons aged 50 to 59] was 9.4 percent for any illicit drug, 5.7 percent for marijuana, and 4.0 percent for nonmedical use of prescription drugs. Analyses show that the observed increases are driven primarily by the aging of the baby boom cohort, which has a much higher lifetime illicit drug use rate than earlier cohorts, representing an increasing proportion of persons aged 50 to 59. Less than 3 percent of past year users initiated drug use at ages 50 to 59. Almost 90 percent of past year users initiated drug use before age 30, and many have been continuing users over the years."

Source

Office of Applied Studies, "OAS Data Review: An Examination of Trends in Illicit Drug Use among Adults Aged 50 to 59 in the United States," (Rockville, MD: Substance Abuse and Mental Health Services Administration, August 2009), p. 8
http://www.oas.samhsa.gov/2k9…