we don't know. https://lorienpsych.com/2021/11/02/ketamine/#11_How_does_ketamine_work https://lorienpsych.com/2021/11/02/ketamine/#11_How_does_ket... the opia

we don't know. https://lorienpsych.com/2021/11/02/ketamine/#11_How_does_ketamine_work https://lorienpsych.com/2021/11/02/ketamine/#11_How_does_ket... the opiate receptor interaction might be important, but it seems that the antidepressant effect persists even if the opiate pathway is blocked (via naltrexone) https://pmc.ncbi.nlm.nih.gov/articles/PMC6439824/ https://pmc.ncbi.nlm.nih.gov/articles/PMC6439824/ (though it's an open-label super small study ... n=4)