Antidepressants are commonly prescribed for chronic pain, including back pain, sciatica, and osteoarthritis. Major pain guidelines recommend the use of serotonin-noradrenaline reuptake inhibitors (SNRIs), most commonly duloxetine. Yet, the evidence for antidepressants in pain is scant.
A new study in the BMJ, led by Giovanni Ferreira at the University of Sydney, Australia, aimed to assess the evidence for these drugs in treating back pain and osteoarthritis. They found that the vast majority of the studies were at high risk of bias, and the outcomes (while statistically significant) did not meet a threshold for clinical success. That is, antidepressants seem to help a little bit more than a placebo would—but not by enough even to be noticeable to a person in pain.
“More than one-quarter of Americans with chronic low back pain are prescribed an antidepressant within three months of a first diagnosis,” the researchers write. “Evidence supporting the use of antidepressants is, however, uncertain.”
The researchers note that previous meta-analyses of the research have been limited in scope—sometimes focusing on a single drug, for instance—and all of them have included only published trials. Ferreira and the other researchers made a point to include unpublished trials since publication bias can often inflate the apparent efficacy of a treatment.
The researchers analyzed data from 33 placebo-controlled trials with a total of 5,318 participants. Most of the trials examined SNRIs (15 trials) or tricyclic antidepressants (TCAs; 14 trials).
Nineteen of the studies assessed back and neck pain. They found that SNRIs did reduce pain in the short term—but that this effect did not meet a threshold for clinical significance.
“The effect of SNRIs was small and below this review’s predetermined threshold of clinical importance,” they write.
TCAs did not reduce back pain.
Six studies assessed sciatica. Based on one trial, SNRIs appeared to significantly reduce pain in the very short term (within two weeks), but three other trials found them ineffective by 3-13 weeks.
TCAs did not reduce sciatica pain.
Eight studies assessed SNRIs for knee osteoarthritis. Again, although there was a statistically significant effect, the researchers write that “The effect of SNRIs was small and below this review’s predetermined threshold of clinical importance.”
No trials investigated long-term outcomes. Almost all of the trials were of very short duration (several weeks).
The researchers also assessed whether people with pain and depression might benefit more from antidepressants than people with pain but no depression. However, they found no evidence for such a benefit.
Because there were very few trials, and because the trials were all at such high risk for bias, the researchers could not fully assess the risk of adverse effects with antidepressants. Drop-outs for adverse effects were higher with SNRIs than with placebo. About two-thirds of people taking SNRIs experienced an adverse effect.
The researchers note that their study was consistent with previous findings.
Ultimately, they write, “Although the observed effect of SNRIs in reducing back pain and related disability was statistically significant, the magnitude of such effects was too small to be considered clinically important.”
In an accompanying editorial, Martin Underwood of the Warwick Clinical Trials Unit (University of Warwick, UK) writes:
“Drug treatments are largely ineffective for back pain and osteoarthritis and have the potential for serious harm. We need to work harder to help people with these disorders to live better with their pain without recourse to the prescription pad.”
Ferreira, G. E., McLachlan, A. J., Lin, C. W. C., Zadro, J. R., Abdel-Shaheed, C., . . . & Chris G Maher (2021). Efficacy and safety of antidepressants for the treatment of back pain and osteoarthritis: systematic review and meta-analysis. BMJ, 372, m4825. DOI: https://doi.org/10.1136/bmj.m4825 (Link)
“anti-depressants” are not good for anything and those who claim to be helped will recognize the harm at some point in their lives. There is no return, damage done.
They are prescribed for chronic conditions for several reasons, all intertwined. First off it is supposed to get rid of patients by then even denying their complaints about the drugs.
It also leaves a nice paper trail so other providers ignore the pain. It also gets the patient demeaning attitudes. Doctors are great at misrepresenting patients, it is an accepted practice now.
They write something completely different than what the client said, and like a schoolyard clique, the medical system listens to the whispers.
These studies suffer the same flaws as other psych studies.
Since 1/4 of people get prescribed the drugs in 3 months that means some of the people in the non drug group in these studies likely had been on the drugs before and are suffering withdrawal.
The drugs also cause many physical effects that are noticeable. Over 80% of people in these trials know who is taking the drugs because of this and therefore an active placebo effect occurs.
Opioid corporations claimed their drugs were safe and effective by using biased/flawed short term studies with the same flaws as psych studies. Low and behold when long term studies and data was done opioids are not safe or effective for chronic pain. Just like how long term studies of psych drugs find the drugs worsen outcomes.
As one who was misdiagnosed with “chronic low back pain,” which was the result of a “bad fix” on a broken ankle, by my PCP’s husband. Who was the “attending physician” at the “bad fix,” on my broken ankle, according to my medical records. I will say that “chronic back pain” was remarkably eliminated, quite quickly, by an old school chiropractor, who I paid for – outside my medical insurance.
“About two-thirds of people taking SNRIs experienced an adverse effect.” I know my PCP inappropriately, and disingenuously, put me on a SNRI, which resulted in very bizarre and adverse effects. Which my PCP, the psychologists, and psychiatrists, all misdiagnosed.
So I totally agree, the antidepressants should NOT be prescribed for back pain.
Perhaps I don’t know enough people with back pain (I myself have some issues given the physicality of my career), but this article’s statistics are shocking to me. I wish my zoloft took away my back pain, damn!
Then again, whatever pharma companies can get away with marketing their pills for (whether or not the pills actually treat it, or if they work at all) shouldn’t really be surprising to people who are informed on how pharma works.
Isn’t this sort of like saying, “Baseball bats are not useful for playing ice hockey?” Even if you buy into the antidepressant mythology, why would they be of any use for back pain? Unless they make it so you feel OK about having back pain and it doesn’t bother you as much?
In depression scales used to measure the effectiveness of these drugs complaining about physical symptoms is marked as “mental illness”. It doesn’t matter if you have those physical symptoms complaint less is a sign the drug “works”. Not Mentioning you feel sad is also marked as less “depressed” even if your level of sadness is the same.
The long term data shows these drugs make people’s mental health worse. I’d say it’s not that the drugs make people not care; it’s that the drugs in effect silence them from verbalizing their suffering.