A survey of more than 12,000 U.S. high-school seniors found that 12.3 percent said they had used opioid-based prescription drugs for non-medical purposes, with 8 percent saying they had done so within the past year, HealthDay News reported Aug. 3.

Students said they used drugs like hydrocodone, oxycodone, hydromorphone, meperidine, morphine and codeine to relax, relieve tension, get high, experiment, relieve pain, or have a good time with their friends.

Those who used the drugs for reasons other than pain relief were more likely to use other addictive drugs and have signs of addictive disorders, researchers said.

"The results of this study provide compelling evidence that adolescents have a wide range of motives for using prescription opioids non-medically, and these motives should be carefully considered in efforts to reduce this behavior," said study author Sean Esteban McCabe of the Substance Abuse Research Center of the University of Michigan. "These results suggest that appropriate pain management and careful therapeutic monitoring could contribute to reductions in the non-medical use of prescription opioids among adolescents."

The study was published in the August 2009 issue of the Archives of Pediatrics and Adolescent Medicine.