Finland develops microbiome-based pill to fight depression

2026-06-29 07:35:00, Shëndeti CNA

Immunotherapy could offer a completely new way to treat people with difficult-to-treat depression, according to a clinical trial led by the University of Bristol, published in JAMA Psychiatry on May 20. In the small pilot study, researchers tested whether tocilizumab, a drug commonly prescribed for inflammatory conditions such as rheumatoid arthritis, could ease symptoms of depression in patients who had not improved with standard antidepressants.

Although the study only included 30 participants with moderate to severe depression, the findings suggest that the drug may help reduce the severity of depression, anxiety, and fatigue, while also improving quality of life.

Scientists investigate the role of inflammation in depression

Most current antidepressants work by targeting brain chemicals like serotonin, dopamine, and norepinephrine. However, about a third of people with depression don’t respond well to these medications. In recent years, scientists have increasingly focused on another possible factor contributing to depression: inflammation. Research has shown that about one in three people with depression have elevated inflammatory markers in their blood, suggesting that the immune system may play a role in triggering symptoms for some patients.

One inflammatory protein that has attracted particular attention is interleukin 6 (IL-6), which helps regulate the body's immune response. Previous studies have linked higher levels of IL-6 to depression. Previous research by the same team used Mendelian randomization, a genetic research method that helps scientists separate cause from chance, to investigate the link. Their findings suggested that inflammation involving the IL-6 pathway may be one of the biological drivers of depression.

An existing arthritis drug was tested in a trial. To explore whether blocking IL-6 could improve symptoms of depression, researchers launched a four-week randomised controlled trial involving people with treatment-resistant depression who also showed signs of low-grade inflammation in blood tests. Thirty participants were recruited through the University of Cambridge and the Cambridgeshire and Peterborough NHS Foundation Trust. Fourteen received tocilizumab, while sixteen received a saline placebo. Participants were monitored over four weeks to track any changes in symptoms.

Because the study was relatively small, the researchers said there was limited statistical evidence for major differences between the two groups. However, people who took tocilizumab generally showed greater improvement over time in several areas, including depression severity, fatigue, anxiety, and overall quality of life. Remission rates were also higher in the treatment group. The researchers reported that 54% of participants who took tocilizumab achieved remission of their depression, compared with 31% in the placebo group. The Number Needed to Treat (NNT) was calculated at 5, meaning that five people would need treatment for one other person to benefit. By comparison, the NNT for SSRIs, the most commonly prescribed antidepressants for moderate to severe depression, is about 7.

Personalized treatments for depression could be the future

Golam Khandakar, Professor of Psychiatry and Immunology from the MRC Integrative Epidemiology Unit (MRC IEU) at the University of Bristol and the NIHR Biomedical Research Centre: Bristol (NIHR BRC: Bristol), and the study's lead author and principal investigator, said: "This paper represents an important milestone in the development of new treatments for depression, particularly difficult-to-treat depression, which affects millions of people in the UK alone. This is one of the first randomised controlled trials to test immunotherapy for depression, the first to test IL-6R as a treatment target and the first to use a targeted approach to select patients most likely to benefit and to show that it works."