Psychedelics Reveal Immune Signatures Linked to Rapid Depression Relief

By Bio-IT World News Staff 

August 20, 2026 | Psychedelic drugs, such as psilocybin and ketamine, could offer a faster, more biologically targeted approach to treating depression in people with cancer, while emerging research suggests immune-system biomarkers may help identify which patients are most likely to respond. Gregory Jones, M.D., assistant professor of psychiatry at The University of Texas MD Anderson Cancer Center, and his team are investigating how the brain and immune system interact in cancer-associated depression. Between 30% and 40% of cancer patients experience depression, although the condition is likely underdiagnosed. 

Unlike conventional antidepressants, which can take weeks to work, ketamine and psilocybin have produced substantial improvements within hours or a day in some patients with treatment-resistant depression. MD Anderson currently has clinical trials evaluating psilocybin-assisted psychotherapy for cancer-associated anxiety and depression, as well as a trial investigating ketamine for refractory depression. 

A recent study published in Molecular Psychiatry (DOI: 10.1038/s41380-026-03777-z) examined several rapid-acting antidepressants and what they have in common at the molecular level. Researchers combined cerebrospinal fluid proteomics from healthy volunteers receiving ketamine with transcriptomic analyses of induced pluripotent stem cells (iPSCs) treated with ketamine, a major ketamine metabolite, LSD, or psilocybin. The team identified slightly more than 100 genes that were convergently upregulated across the four compounds. 

Among the key biomarkers were interleukin-15 (IL-15) and interleukin-7 (IL-7). In a post-hoc analysis of data from a randomized, placebo-controlled ketamine trial, higher IL-15 RNA levels were associated with depression relief. IL-7 was associated both with clinical improvement and increased gamma power measured by magnetoencephalography, a brain activity measure described as a leading biomarker of ketamine response. 

The findings point toward a model in which psychedelics do not simply suppress inflammation. Instead, they may recalibrate immune signaling in ways that support neuroplasticity and recovery. IL-15 and IL-7 could ultimately help guide treatment selection based on the biological response to psychedelics. 

The researchers are now looking to determine whether the same immune signature emerges in patients receiving psilocybin. Meanwhile, MD Anderson is preparing for the NeuroGuard trial, which will investigate whether repeated psilocybin dosing can prevent chemotherapy-induced peripheral neuropathy in patients with breast, colorectal, and head and neck cancers. 

To read the full story by Deborah Borfitz, head over to Clinical Research News.