Immunotherapy Shows Promise for Treating Depression
Recent findings from an early clinical trial suggest that immunotherapy might be beneficial for patients with depression who don’t respond to standard antidepressants.
Researchers at the University of Bristol explored the use of tocilizumab, an anti-inflammatory medication typically prescribed for immune disorders like rheumatoid arthritis, to see if it could alleviate symptoms of challenging depression.
It’s known that approximately one in three individuals suffering from depression do not find relief with traditional medical treatments, which usually focus on chemical processes in the brain. Moreover, around one in six adults in the UK will face moderate to severe depressive symptoms at some point in their lives.
Tocilizumab functions by blocking the IL-6R receptor, effectively stopping inflammatory signals associated with autoimmune disorders from binding to cells.
The trial included 30 participants grappling with moderate to severe depression who had not found success with standard antidepressants. Over four weeks, these individuals were randomly assigned to receive either tocilizumab or a placebo.
While the results didn’t show significant statistical differences between the groups, which is often expected in small studies, those who received tocilizumab seemed to show more substantial improvement in various aspects over time. These included overall depression severity, fatigue levels, anxiety, and quality of life.
Golam Khandakar, a professor of psychiatry and immunology at Bristol medical school and one of the study’s senior authors, remarked that this trial is an “important milestone” in seeking new solutions for difficult-to-treat depression.
“This is among the first randomized controlled trials to explore immunotherapy for depression and particularly to look at IL-6R as a target. We’ve also uniquely selected patients most likely to benefit,” Khandakar noted, indicating that the results are promising.
Participants receiving tocilizumab were also more likely to achieve remission from depression—54% compared to 31% in the placebo group. This is noteworthy, as the number needed to treat (NNT) was 5, meaning five patients would need treatment to see one improvement. In comparison, the NNT for SSRIs, common first-line antidepressants for moderate to severe depression, is around 7, suggesting that immunotherapy might be a more effective option.
Though the trial’s sample size was small, the researchers indicated it provides initial evidence that some immunotherapy approaches could effectively lessen depression symptoms.
Dr. Éimear Foley, a senior research associate in immunopsychiatry and co-author of the study, commented, “Depression affects an estimated 10-20% of the global population over their lifetimes, and many patients struggle with existing treatments.”
“Our research brings us closer to personalized care for depression, where treatment options are better tailored to a person’s biology. This will enhance our ability to deliver appropriate treatments at the right time to the right patients.”
