About one in three people with major depression respond poorly to standard antidepressant treatments. This kind of depression is called treatment-resistant depression, and it can lead to long-term disability, financial challenges, and a higher risk of suicide.
Psilocybin-a compound found in certain mushrooms-has shown early promise as a new treatment for this difficult-to-treat depression. Scientists believe it works by affecting a specific brain receptor (called 5-HT2A), which helps the brain become more flexible and adaptable. But there's another possible mechanism of psilocybin that hasn't been studied much: its ability to influence the immune system.
Recent research suggests that inflammation in the body might play a role in depression, especially when treatments don't work. High levels of certain inflammatory markers (called cytokines) are linked to poor response to antidepressants, while lower levels are tied to feeling better. Psilocybin may help reduce this inflammation, which could be part of why it helps some people feel better.
Still, we don't fully understand how a person's inflammation levels before treatment, and how those levels change afterward, relate to how well psilocybin works. Figuring this out could help doctors better match patients to psychedelic therapy and discover new ways to treat depression.
In this study, blood samples from a recent study (called the PsiDeR trial) that tested psilocybin in people with treatment-resistant depression will be analyzed. Cytokine levels in these blood samples, as well as levels of another type of molecule linked to inflammation, called mRNA, will be measured.