By Dan Adkins

"(W)ith carefully targeted campaigns that achieve high levels of reach and frequency, and with messages designed specifically for the target audience ... we believe public service announcements can play an important role in future drug abuse prevention efforts."

“…(W)ith carefully targeted campaigns that achieve high levels of reach and frequency, and with messages designed specifically for the target audience … we believe public service announcements can play an important role in future drug abuse prevention efforts,” report communications professors Philip Palmgreen and Lewis Donohew and psychology professors Elizabeth Lorch and Rick Hoyle.

The findings are reported in “Television Campaigns and Adolescent Marijuana Use: Tests of Sensation Seeking Targeting” in the February 2001 issue of the American Journal of Public Health.  Also an investigator in the study was Michael T. Stephenson, a communications professor at the University of Missouri-Columbia.

The study evaluated the impact of anti-marijuana ads that target “high-sensation seeking” teen-agers who show a high risk of substance abuse (about half the population).  The researchers surveyed 3,174 youths in Lexington, Ky., and 3,197 youths in Knoxville, Tenn., for 32 months from May 1996 to December 1998.  During that time, two four-month campaigns of anti-drug ads were run in Lexington, with each campaign separated by several months without ads.  Knoxville’s teen-agers were exposed to one campaign.

The campaigns were designed to expose at least 70 percent of the targeted age group to the ads at least three times a week.

In Lexington, the first campaign interrupted a trend of increasing marijuana use among high-risk teens, causing a decline that ended shortly before the second campaign.  The second campaign also coincided with a decline in drug use.

In Knoxville, the researchers found the ads also interrupted an increase in marijuana use among high-risk teens and resulted in declines.

“In Knox County (Tenn.), effects were still evident several months after the campaign.  There, the estimated drop in the relative proportion of high-sensation seekers using marijuana was 26.7 percent,” the researchers said.

“This estimate is conservative,” Palmgreen said.  ”Without the campaign these kids would have continued to increase their marijuana use as they got older. The actual proportional reduction in use was probably over 35 percent.   The total reductions in Lexington were even larger, because there were two campaigns.”

Palmgreen serves on a national task force overseeing a $1 billion federal advertising campaign to reduce illegal substance abuse.  Many of the ads being used in the campaign use techniques based on ads prepared by Palmgreen, Donohew, and associates that specifically target high-sensation seekers. As Palmgreen observed,  “This is the first really solid evidence that televised anti-drug ads can produce substantial reductions in actual drug use.”