A major study of the effectiveness of televised antidrug public service announcements (PSAs) brought new hope to researchers, clinicians, and antidrug groups seeking to curb addictive behaviors.

The results of the study, published in the February issue of the American Journal of Public Health, show a 27 percent to 38 percent drop in marijuana use by teens after exposure to numerous PSAs depicting some of the dangers of marijuana use.

According to the University of Michigan’s Monitoring the Future Study, marijuana use in teens is growing rapidly. Lifetime prevalence for 12th graders rose from 32.6 percent in 1992 to 49.7 percent in 1999.

Hoping to reduce these numbers, Philip Palmgreen, Ph.D., worked with the National Institute on Drug Abuse (NIDA) to test the power of PSAs to reduce marijuana use. NIDA funded the 32-month long study.

Palmgreen, a professor of communications at the University of Kentucky in Lexington, tested the effects of five televised antimarijuana PSAs targeted at high sensation-seeking (HSS) adolescents. HSS teens exhibit a need for novel, complex, or emotionally intense stimuli.

Psychologist Marvin Zuckerman, Ph.D., has done a great deal of research on the subject, and first coined the term "high sensation seeking" about 40 years ago, according to Palmgreen. Zuckerman has written two books on the subject, and the latest is titled Sensation Seeking: Beyond the Optimal Level of Arousal, published in 1994 by Cambridge University Press.

Palmgreen and his team of researchers developed the Sensation Seeking Targeting Approach (SENTAR) using the sensation-seeking trait as the basis. The strategy applies high sensation-value prevention messages, or more specifically, dramatic and attention-grabbing PSAs to attract the attention of HSS teens.

Palmgreen targeted the HSS teens because they have a higher risk of using drugs and at an earlier age, according to Palmgreen. "HSS teens are more sensitive to the rewarding effects of the drugs on the brain, like the dopamine rush," he said.

"We know how to design messages for HSS youths," said Palmgreen, who stressed that the sensation-seeking personality trait gives researchers an idea of how to stage an intervention. "If you take another risk factor like deviance, for example, it doesn’t tell you how to design the messages." Palmgreen said that previous research has determined that HSS teens have the highest response rates to high-sensation value messages, which are likely to be unconventional, graphic, or explicit or involve emotionally powerful scenes.

Five televised PSAs appeared between January and April 1997 in Fayette County, Ky. Similar campaigns were launched there again and in Knox County, Tenn., between January and April 1998. Researchers placed the ads during television programs that were most likely to be watched by HSS teens, as determined by survey before the spots aired. These notable programs included "The Simpsons" and "StarTrek: The Next Generation." The PSAs were designed to appeal to those teens who tested high on sensation seeking as determined by the Brief Sensation-Seeking Scale. The teens were asked to respond by degree to eight statements including "I like wild parties," "I prefer friends who are excitingly unpredictable," and "I would like to take off on a trip with no preplanned routes or timetables."

According to the precampaign interviews, 50 percent of the teens were high sensation seekers.

One 30-second spot from the campaign features a teen named Michael hanging out with a friend and smoking marijuana. As the words "A True Story" are splashed across the screen in red letters, the teen said that he "liked the way that marijuana made him feel, like he could do crazy things around his friends." One of those crazy things was a fateful game of Russian roulette. As the camera zooms in on Michael placing a gun against his temple, the screen goes blank. Next, Michael is seen in a wheelchair staring out a window. "I take medication every day to stop my convulsions," Michael said. "I only smoked for a few months, but now I’m on drugs for life."

Before this and four other spots aired, researchers interviewed the teens. To find the extent of teen marijuana use prior to the campaigns and to assess the effect of the campaigns on marijuana use, researchers interviewed 100 randomly selected public school students in each county once a month for 32 months. In all, more than 3,000 teens were interviewed in each county. The interviews started eight months before the first PSA campaign and ended eight months after the last.

Marijuana use among the youths was found to be close to figures reported in NIDA’s Monitoring the Future Study. In 1998 NIDA found that between 22 percent and 24 percent of 12th graders had used marijuana. In Fayette and Knox counties, 25.5 percent and 20.3 percent of 12th graders, respectively, had used marijuana in the preceding 30 days.

Effects from the single campaign in Knox County were still evident several months after its conclusion. There, the estimated drop in the relative proportion of HSS teens using marijuana was 26.7 percent. In Fayette County, the drop in marijuana use for HSS teens was estimated to be approximately 38 percent. For low-sensation-seeking teens, both marijuana usage rates and reactions to the PSAs were much lower than those of HSS teens.

The study has received a great deal of positive response from around the nation, according to Palmgreen. Antidrug groups such as Partnership for a Drug Free America and Drug Abuse Resistance Education have expressed interest in using the spots.

Michael Blumenfield, M.D., chair of APA’s Joint Commission on Public Affairs, is intrigued by the implications of the PSA study. "Not only do the findings demonstrate the effectiveness of certain PSAs on drug use for the first time," Blumenfield told Psychiatric News, "but this approach might be effective in other areas of psychiatry, such as suicide prevention."

Palmgreen agreed and plans to study the effects of PSAs on other risky behaviors. He added, " In any public health campaign directed at risk-related behavior among adolescents, research should target high-sensation seekers." His next research project will use PSAs targeted at HSS teens to reduce risky sexual behavior and the instance of HIV. ▪