The review examined 176 trials and included nearly 30,000 patients, but most looked at patients’ experiences over only a couple of months. Among the drugs studied, which included Prozac and a cheap antidepressant called amitriptyline, only one, called duloxetine, showed any evidence for pain relief, and even then, only in the short term.

However, patients are advised to stay on medication if it works for them, and they must not suddenly stop taking tablets without consulting a doctor. NHS guidelines recommend the use of antidepressants for some chronic-pain conditions, including nerve pain and fibromyalgia, instead of strong opioid painkillers, which can be addictive. Simple painkillers such as paracetamol and ibuprofen are also not recommended.

Chronic pain, which lasts for more than three months, is a common problem, affecting one out of every four people in the UK, according to a BBC News survey. The condition can be caused by various factors, including arthritis or an unknown cause. Experts suggest that antidepressants may help because brain systems for mood and pain overlap considerably.

However, the lack of long-term safety and effectiveness data for antidepressants in treating chronic pain is “shocking,” according to the review’s lead author, Prof Tamar Pincus. She warns that this is a global public-health concern, and patients are being prescribed medication without sufficient scientific proof that it helps, nor an understanding of the long-term impact on health.

Clinical lead for the National Institute for Health and Care Excellence (NICE) chronic-pain guidelines, Dr Cathy Stannard, says the review adds to the substantial evidence showing that the use of medicines to treat long-term pain is disappointing. She emphasizes that existing services, usually outside healthcare, including support with mobility, debt management, trauma, and social isolation, can be helpful for people living with pain. Identifying what matters most to people and signposting to appropriate local support is a promising way forward.

When coming off antidepressants, the medication should be slowly reduced over weeks to prevent withdrawal symptoms, according to the NHS.