Prescribing antidepressants for chronic pain lacks evidence, experts say

Researchers have warned there is a lack of evidence around prescribing antidepressants for chronic pain.

Guidance from the National Institute for Health and Care Excellence (Nice) in 2021 recommends that an antidepressant (amitriptyline, citalopram, duloxetine, fluoxetine, paroxetine or sertraline) can be considered for people aged 18 and over with pain lasting longer than three months which cannot be accounted for by another diagnosis.

The guidance said the drugs may help with quality of life, pain, sleep and psychological distress, even in the patient is not suffering depression.

A separate guideline on neuropathic (nerve) pain recommends offering a choice of treatments, including amitriptyline and duloxetine, alongside a discussion on possible benefits and side-effects.

However, researchers writing in the British Medical Journal (BMJ) on Wednesday have warned that recommending antidepressants for pain is not always backed by evidence.

The team, including academics from the University of Warwick, reviewed existing research on the the safety and effectiveness of antidepressants in the treatment of chronic pain.

Their work included 26 reviews from 2012 to 2022 involving more than 25,000 people and looked at 22 pain areas including back pain, fibromyalgia, headaches, post-operative pain and irritable bowel syndrome.

The study found no review could provide high certainty evidence on the effectiveness of antidepressants for pain for any condition.

Nine reviews did provide evidence that some antidepressants were effective, such as moderate evidence suggesting serotonin-norepinephrine reuptake inhibitors (SNRIs), such as duloxetine, were effective for back pain, post-operative pain, fibromyalgia and nerve pain.

However, the study only found low certainty evidence that selective serotonin reuptake inhibitors (SSRIs) were effective for people with depression and pain related to other conditions, and that tricyclic antidepressants (TCAs) were effective for irritable bowel syndrome, nerve pain and chronic tension-type headaches.

In 31 comparisons, antidepressants were either not effective or the evidence was inconclusive.

Professor Martin Underwood from the University of Warwick, said: “There is a role for antidepressants in helping people living with chronic pain, however, this is more limited than previously thought.

“Antidepressants may have unpleasant side effects that patients may wish to avoid.

“We need to work harder to help people manage their pain and live better, without relying on the prescription pad.”

Lead author Dr Giovanni Ferreira, from the University of Sydney, said a more nuanced approach to prescribing antidepressants for pain is needed.

He added: “Recommending a list of antidepressants without careful consideration of the evidence for each of those antidepressants for different pain conditions may mislead clinicians and patients into thinking that all antidepressants have the same effectiveness for pain conditions.

“We showed that is not the case.”

Co-author Dr Christina Abdel Shaheed, from the University of Sydney, said: “Some pain medicines may have a role in pain management, but they need to be considered as only part of the solution.

“For some pain conditions, exercise, physiotherapy, and lifestyle changes may also help.

“Speak to your health professional to learn more about what alternatives might be appropriate for you.”

Dr Benjamin Ellis, senior clinical policy adviser at Versus Arthritis and a consultant rheumatologist, said: “Arthritis and musculoskeletal conditions can cause agonising pain and disability, but treatment options remain limited.

“We know antidepressant medicines don’t help with osteoarthritis pain, though can help with anxiety or depression which can be a consequence of having pain, and it seems people may be prescribing these to patients out of desperation, and a shortage of more effective treatments.

“More and better research is needed into effective pain management medicines and strategies, putting the needs of people with pain at the heart, and looking beyond simply reducing the pain itself towards dealing with its consequences, such as depression, fatigue, and unemployment.

“Frankly, it’s a scandal that people with arthritis and chronic pain struggle to access the physical activity, mental health, and employment support that we know is safe, effective and can transform lives.”