Substance abuse among Americans ages 50 to 59 nearly doubled, from 2.7 percent in 2002 to 5.0 in 2007, according to a report from the Substance Abuse and Mental Health Services Administration (SAMHSA). Researchers link the spike to the aging Baby Boomer generation, which has a higher drug use rate than previous generations.

The August 2009 report—“An Examination of Trends in Illicit Drug Use among Adults Aged 50 to 59 in the United States”—found that of the Baby Boomers who have used illegal substances during their lifetime, one in seven took drugs again in the past year.

Medical authorities are worried about the healthcare effects this trend will have on the middle-aged generation.

As the human body ages, its metabolism decreases and body water content lowers. This means that even when using small amounts of a drug, an older adult can have a longer “high” than someone younger—affecting the older person’s movement and increasing the risk of falls, injuries and other accidents.

This increased sensitivity and decreased tolerance to drugs means a substantial risk of overdose for older users.

Also, many Baby Boomers use prescription drugs, which can be deadly when mixed with illegal substances.

SAMHSA projects that the number of drug users ages 50-59 will increase as future generations reach this age demographic.

The government organization said that over the coming years “the United States faces the challenge of reducing drug use and treating drug use disorders and associated health conditions” among this age group.