In a double-blind, placebo-controlled trial with 72 participants, ayahuasca's effects on depression-related biomarkers were examined two days after dosing. Larger reductions in depressive symptoms during the session were linked to higher serum cortisol levels in patients with treatment-resistant depression. Smaller changes in salivary cortisol during ayahuasca use were associated with higher brain-derived neurotrophic factor (BDNF) levels in patients who showed greater clinical improvement in depressive symptoms. No moderating effects were found for the cortisol awakening response, interleukin-6, or C-reactive protein in patients, nor for any biomarker in healthy controls or the placebo group. The findings suggest that acute emotional and physiological responses during ayahuasca sessions may influence key biomarkers of depression.
In a small open-label trial of 22 patients with treatment-resistant depression who received seven weekly subcutaneous doses of esketamine, those with elevated baseline C-reactive protein (CRP > 1 mg/L) showed significant reductions in CRP by week 4 and week 8, while patients without inflammation showed no change. By week 8, CRP levels in both groups were comparable. Although the inflammation group had a greater average reduction in depression severity (15.88 points on the MADRS scale versus 11.14 points), this difference was not statistically significant, and changes in CRP did not predict symptom improvement. Larger controlled studies are needed.