Convergent neuroimmune signaling underlying rapid antidepressant response to ketamine and psychedelics.

In 30 seconds

This multimodal study examined neuroimmune correlates of rapid antidepressant response to ketamine and serotonergic psychedelics, combining CSF proteomics, treated iPSC-derived cells, and clinical measures in participants with treatment-resistant depression (TRD) and healthy volunteers. In participants receiving a single intravenous ketamine dose or placebo, immune signaling involving IL-7 and IL-15 was associated with blood transcriptional patterns, MEG gamma power, and antidepressant response. Cytokine ratios predicted response (IL-4/IFN-γ, p FDR < 0.041) and non-response (MCP-1/IL-7, p FDR < 0.009), supporting a potential role for immune balance in treatment-related effects.

Key findings

• Across CSF and iPSC-neuron analyses, conserved immune pathways emerged, with IL-15 and MCP-1 identified as regulatory hubs.
• Ketamine responders showed lower baseline IL-15 and higher B-cell signaling in whole blood; these patterns reversed after treatment.
• Plasma IL-7 correlated with baseline MEG gamma power (main effect p FDR < 0.05), with a stronger association in TRD subcortical regions (diagnosis x IL-7 p FDR < 10 -14).
• Cytokine ratios predicted antidepressant response (IL-4/IFN-γ, p FDR < 0.041) and non-response (MCP-1/IL-7, p FDR < 0.009).

Why it matters

The findings connect peripheral immune signaling with brain activity and clinical response in ketamine-treated TRD, while identifying pathways also examined across ketamine and psychedelic exposures. This may help frame future research into biological variation in rapid antidepressant response, although the reported associations do not establish that cytokine changes cause clinical benefit.

What to keep in mind

The study integrates several experimental and clinical datasets, and the abstract does not report a direct clinical comparison of ketamine with psychedelics; the clinical response findings concern ketamine.