Thousands take antidepressants for pain without proof they work – experts

In the largest study of its kind, experts looked at medicines commonly prescribed on the NHS including amitriptyline, duloxetine, fluoxetine (Prozac), citalopram, paroxetine (Seroxat) and sertraline.

Amitriptyline is one of the most commonly prescribed antidepressants for chronic pain in England, with the NHS website saying it can treat nerve pain, some back pain and can help prevent migraines.

But the new study, which included 176 trials and almost 30,000 patients, concluded that only duloxetine had reliable evidence for pain relief.

Researchers, including from the universities of Southampton, Bath, Bristol and University College London, also raised concerns about the lack of long-term data on safety.

The National Institute for Health and Care Excellence (Nice) recommends a range of antidepressants as an option for chronic primary pain (where the underlying cause is unknown) and neuropathic pain such as neuralgia, some cancer pain and conditions that can cause neuropathic pain such as stroke, spinal cord injury and multiple sclerosis.

It told the PA news agency it had reviewed the new evidence but concluded it was “not sufficient to warrant an update to the recommendations in our chronic pain guideline at this stage”.

But Professor Tamar Pincus, lead author of the new study from 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."

University of Southampton researcher Dr Hollie Birkinshaw said the clinical trials investigated three pain types: fibromyalgia, nerve pain and musculoskeletal pain (mainly low back pain and osteoarthritis), with duloxetine and amitriptyline among the most frequently studied antidepressants.

She said researchers found that the safety data for adverse events, serious adverse events and withdrawal “was very poor”, adding: “So we can’t draw any reliable conclusions, unfortunately, for the safety of antidepressants or unwanted effects, from our data.”

Dr Birkinshaw said the only “consistent picture” on effectiveness was for duloxetine” but not for other antidepressants used in the UK.

“This includes amitriptyline, so even though it’s the most common antidepressant used clinically, most of the studies were small and it’s not reliable evidence,” she said.

Statistician Gavin Stewart, review co-author from Newcastle University, said the team was now calling on Nice and the US Food and Drug Administration to update their guidelines “and on funders to stop supporting small and flawed trials”.

The authors urged people not to come off their drugs but to speak to a GP if they had concerns.

A Nice spokesman said: “Our guideline on chronic pain published in 2021 recommends antidepressants, including duloxetine, can be considered for people aged 18 years and over to manage chronic primary pain, after a full discussion of the benefits and harms. This is because the evidence shows these medicines may help with quality of life, pain, sleep and psychological distress, even in the absence of a diagnosis of depression."

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