New types of anti-inflammatory drugs could be used to treat depression, researchers have discovered. In a review of 20 clinical trials, researchers found anti-cytokine drugs had a significant antidepressant effect when compared to a placebo – potentially providing a new avenue of treatment for those who are resistant to traditional drug therapies.
Research is increasingly showing inflammation is involved in the development of depression. Normally, when the body is exposed to an infection, the immune system fights it off with proteins called cytokines. While always present in the body, these inflammatory markers rise in response to infection.
However, inflammation can also take place when the immune system goes wrong and mistakes healthy cells for infected ones. This leads to autoimmune inflammatory disease including Crohn's disease and rheumatoid arthritis. Recently, anti-cytokine drugs have been developed to treat these diseases.
In a study published in Molecular Psychiatry, researchers from the University of Cambridge note that previous work has shown children with high levels of inflammatory markers while healthy are more at risk of developing depression in adulthood – indicating the immune system is involved.
To look at the potential benefit of anti-cytokines, they analysed data from clinical trials that use these drugs to treat a range of autoimmune inflammatory diseases. Their findings showed the drugs alleviated the symptoms of depression separately from the physical conditions. Indeed, they showed there was a significant anti-depressant effect when compared to a placebo.
Study leader Golam Khandaker said: "It's becoming increasingly clear to us that inflammation plays a role in depression, at least for some individuals, and now our review suggests that it may be possible to treat these individuals using some anti-inflammatory drugs. These are not your everyday anti-inflammatory drugs such as ibuprofen, however, but a particular new class of drugs."
The team said it is too early to know if these drugs can be used to treat depression in a clinical setting – further trials will be required to establish this and potential side effects must be considered.
However, Khandaker says they could provide a treatment option where antidepressants are ineffective. "About a third of patients who are resistant to antidepressants show evidence of inflammation," he said. "So, anti-inflammatory treatments could be relevant for a large number of people who suffer from depression."