Most Antidepressants Ineffective At Treating Chronic Pain

More than 51 million U.S. adults live with chronic pain. Out of that, at least 17.1 million people suffer through high-impact chronic pain on a daily basis, according to the Centers for Disease Control and Prevention. Doctors commonly prescribe anti-depressants to people living with chronic pain. But a recent study suggests that might not be the best approach to provide pain relief.

In the UK-based study, researchers reviewed and analyzed studies that investigated the efficacy of 25 different antidepressants. They observed that the only antidepressant that might be useful in treating chronic pain is duloxetine. Whereas they highlighted that the “evidence for all other antidepressants was low certainty.”

The team narrowed down 176 studies that included 28,664 people with chronic pain. Only 146 of these studies revealed their sources of funding. And out of that, pharmaceutical companies had funded 72 studies. These studies delved into whether antidepressants help in relieving pain among people living with fibromyalgia, nerve pain, and lower back pain. The most common anti-depressants prescribed for pain relief are amitriptyline, duloxetine, and milnacipran. All over the world, amitriptyline is the most popular antidepressants that doctors prescribe for pain relief. In England itself, 10 million prescriptions of amitriptyline were given to patients.

“We are only confident in the effectiveness of one antidepressant: duloxetine. We found that a standard dose (60 mg) was effective, and that there is no benefit to using a higher dose,” the researchers wrote in their study. “We are uncertain about unwanted effects for any antidepressant as the data for this were very poor. Future research should address this.”

They found that for every 1000 people who were taking duloxetine for pain relief, 435 reported they experienced 50% of pain relief but the control group, or those who were given placebo treatment, also experienced 50% pain relief. The findings were published in the Cochrane Database of Systematic Reviews on May 10, 2023.

In a press release, lead author of the study, Tamar Pincus, a professor at the University of Southampton said, “This is a global public health concern. Chronic pain is a problem for millions who are prescribed antidepressants without sufficient scientific proof they help, nor an understanding of the long-term impact on health.”

“Our review found no reliable evidence for the long-term efficacy of any antidepressant, and no reliable evidence for their safety for chronic pain at any point. Though we did find that duloxetine provided short-term pain relief for patients we studied, we remain concerned about its possible long-term harm due to the gaps in current evidence,” he further added.

In another recent study published in the British Medical Journal in January 2023, researchers reported that antidepressants were ineffective for treating pain conditions and that the evidence was “inconclusive.” The BMJ study also noted that there was some evidence for the efficacy of duloxetine when prescribed at doses between 60-120 mg for conditions like back pain, fibromyalgia, and neuropathic pain. The researchers’ conclusion stated: “Our findings suggest that a more nuanced approach is needed when prescribing antidepressants for pain.”