Still hurting

Antidepressants are often used for pain relief, but new research shows they might not be as effective as first thought - or even the best option.

- Nicky Pellegrino

Consumption of antidepressants has more than doubled in OECD countries over the past 20 years, and the often off-label use of these medicines to treat chronic pain conditions is believed to be contributing to the increase.

Many people are dealing with ongoing pain about one in five globally- and yet drug options for treatment are limited and the potential harm of many medications may outweigh the benefits. Opioids are highly addictive, for instance, and long-term use of anti-inflammatories can have numerous adverse effects, including kidney and gastrointestinal risks.

In its most recent guidelines for managing primary chronic pain (defined, in this case, as pain with no clear underlying cause, or pain or its impact that is out of proportion to any observable injury or disease), the UK's National Institute for Health and Care Excellence (Nice) recommended against using any pain medicine, with the exception of antidepressants.

The guidelines sparked curiosity in researchers at the University of Sydney's Institute for Musculoskeletal Health. After all, a lot of diverse health problems are grouped together and defined as chronic pain conditions, from fibromyalgia to irritable bowel syndrome. And the term antidepressants is used to describe a range of very different drugs.

Led by Dr Giovanni Ferreira, the researchers reviewed all the existing evidence about the effectiveness of antidepressants to treat chronic pain, delving into data covering 22 pain conditions and eight different classes of the drug.