Long-term use of prescription painkillers ups depression risk
Narcotic pain killer addiction is on the rise, quickly becoming one of the nation's most dangerous substance abuse problems.
And new research confirms that long-term use of prescription opioid analgesics also poses another problem: depression.
A team led by a Saint Louis University researcher Jeffrey Scherrer, Ph.D., found that risk of major depression increased significantly in patients who had a history of opioid use.
Longer exposure = greater risk
The study analyzed medical records of about 50,000 veterans who had no history of opioid use or depression and who were then prescribed narcotic pain killers.
Patients who remained on opioids for longer than 180 days showed a 53-percent increased risk of developing depression. Those who used opioids for 90-180 days had a 25-percent increased risk for depression, compared with patients who never took narcotic pain killers for longer than 1-89 days.
"These findings suggest that the longer one is exposed to opioid analgesics, the greater is their risk of developing depression," Dr. Scherrer said. "Opioids have long been known to allay pain and suffering, but reports of adverse effects are abundant and continue to emerge."
Several factors might be involved in the opioid use-depression link, Dr. Scherrer said. Opioids may reset the brain's "reward" pathway, which means that chronic use of narcotic painkillers makes it harder for a person to experience pleasure from natural reward-type behavior, like sex or eating.
Other factors might include physical pain that results after opioid use has stopped, or adrenal, vitamin D or testosterone deficiencies that can develop.
"Preliminary evidence suggests that if you can keep your daily dose low, you may be at lower risk for depression," he said. "Even though the risk is not huge, there is enough exposure that we may have a public health problem," he said.
The study is published in the Journal of General Internal Medicine.
Source: Saint Louis University Medical Center