Opioids may cause short-term improvement in mood, but long-term use imposes risk of new-onset depression, according to a study published online in the Annals of Family Medicine.
Long-term opioid use of more than 30 days may lead to changes in neuroanatomy and low testosterone, among other possible biological explanations, according to Jeffrey Scherrer, PhD, Saint Louis University, St. Louis, Missouri, and colleagues.
The link was independent of the known contribution of pain to depression, and the study calls on clinicians to consider the contribution of opioid use when depressed mood develops in their patients.
“Opioid-related new onset of depression is associated with longer duration of use but not dose,” the authors wrote. “Patients and practitioners should be aware that opioid analgesic use of longer than 30 days imposes risk of new-onset depression.”
The study calls for additional research to identify which patients are most vulnerable to opioid-related depression.
For the study, the researchers collected patient data from the Veterans Health Administration (VHA), Baylor Scott & White Health (BSWH), and the Henry Ford Health System (HFHS) from 2000 to 2012.
The data sets were comprised of 70,997 VHA patients, 13,777 BSWH patients, and 22,981 patients from HFHS. The patients were new opioid users, aged 18 to 80 years, without a diagnosis of depression when they began taking medication.
Twelve percent of the VHA sample, 9% of the BSWH sample, and 11% of the HFHS sample experienced new-onset depression after opioid analgesic use.
“Findings were remarkably consistent across the 3 healthcare systems even though the systems have very different patient characteristics and demographics,” said Dr. Scherrer.
In all 3 patient populations, longer duration of opioid analgesic use was associated with new-onset depression after controlling for pain and daily morphine equivalent doses.
The authors noted that research on the efficacy of opioids in depression treatment, while limited by small samples, short follow-up times and lack of control groups, does not support opioids as an effective long-term treatment for depression.
Opioid drugs in the study included codeine, fentanyl, hydrocodone, hydromorphone, levorphanol, meperidine, oxycodone, oxymorphone, morphine, and pentazocine.