Depression: New blood test could result in personalised treatment

ABC News
June 7, 2016

Scientists have developed a blood test that can predict whether people with depression will respond to common anti-depressants, a discovery that could bring in a new era of personalised treatment for people with the debilitating mental illness.

The researchers said doctors should in future be able to direct depressed patients with a certain level of inflammation in their blood towards earlier treatment with a more potent course of anti-depressants — possibly including combining two medications — before they get worse.

"This study moves us a step closer to providing personalised anti-depressant treatment at the earliest signs of depression," said Annamaria Cattaneo, who led the work at King's College London's Institute of Psychiatry, Psychology & Neuroscience (IoPPN).

Depression is one of the most common forms of mental illness, affecting more than 350 million people worldwide.

It is ranked by the World Health Organisation as the leading cause of disability globally.

Treatment usually involves either medication, some form of psychotherapy, or a combination of both. But around half of all people treated for depression fail to get better with first-line antidepressants, and around a third of patients are resistant to all available medications designed to help.

Patients often treated with trial-and-error approach

Until now, doctors have not been able to establish whether someone will respond to an anti-depressant, or whether they might need a more-aggressive treatment plan from the start.

As a result, patients are often treated with a trial-and-error approach, trying one drug after another for months on end and often seeing no improvement in their symptoms.

In this study, published on Tuesday in the International Journal of Neuropsychopharmacology, Cattaneo's team focused on two biomarkers that measure blood inflammation.

Previous studies have already linked raised levels of inflammation with a poor response to anti-depressants.

The researchers measured the two markers, called Macrophage Migration Inhibitory Factor (MIF) and interleukin (IL)-1, in two groups of patients with depression before or after they took a range of commonly prescribed anti-depressants.

They found blood readings above a certain threshold could reliably predict the probability of a patient responding.

Patients with MIF and IL-1levels above the thresholds had a 100 per cent chance of not responding to conventional, commonly prescribed anti-depressants, the researchers found, while those with lower levels did show a positive treatment response.

Carmine Pariante, a IoPPN professor who worked on the team, said the results point to a "clinically suitable approach for personalising anti-depressant therapy".

University of Queensland Health expert Dr Caroline Salom said this new development would allow for a more appropriate use of anti-depressants.

Dr Salom said the origins of patients' depression and their responses to therapy were not always the same.

She highlighted the differences between each patient and the benefits the treatment would provide, with technicians given the ability to find the right treatment, tailored to each patient's needs.

"The testing would predict whether someone is likely to respond [or] not respond to a specific type of anti-depressant," she said.

"This would reduce some of the process by which an effective treatment program can be established."

ABC/ Reuters

This page reproduces a page on the ABC News website.