Study finds common risk factors linked with painkiller addiction

A new Geisinger study begins to unlock the puzzle of painkiller (opioid) addiction - why some people are more likely to become addicted than others. Geisinger investigators have found that patients with four common risk factors have a significantly higher risk of addiction. In addition, a history of severe drug dependence and drug abuse compounds the risk. The findings appear in the September issue of Addiction.

According to the Geisinger study, common risk factors for painkiller addiction in patients with chronic pain are: age (65 years or younger), a history of drug abuse and depression, and use of psychiatric medications. Currently, statistics find painkiller addiction as high as one in four (26 percent) among these patients.

Significance of findings
"These findings suggest that patients with pre-existing risk factors are more likely to become addicted to painkillers, providing the foundation for further clinical evaluation," said Joseph Boscarino, Ph.D., an epidemiologist and senior investigator at Geisinger's Center for Health Research. "By assessing patients in chronic pain for these risk factors before prescribing painkillers, doctors will be better able to treat their patients' pain without the potential for future drug addiction."

The study suggests that the same risk factors, often noted in a patient's medical record, may also influence drug addiction in patients without a history of chronic pain.

How it was done
For this study, Geisinger investigators accessed Geisinger's electronic data base to identify patients with back pain and related orthopedic conditions who were prescribed painkillers (opioids) for more than 90 days. They interviewed a sample (705) of these patients and collected and studied their DNA.

Specifically, investigators studied a gene located on chromosome 15 that has been implicated in alcohol, cocaine and cigarette smoking dependencies. The data suggests an association of DNA variants in a gene cluster on chromosome 15 with opioid as well as nicotine addiction. While the association of this locus with smoking phenotypes is well known, the association with opioid dependence is unknown.

Investigators also looked at patient demographics (age, sex, income and education), psychological factors, exposure to stress and childhood trauma, history of previous substance abuse, genetics and other potential risk factors.