No. We don't. While obviously, we know it inhibits serotonin reuptake, we do not know why that SSRI action works. They were developed based on the monoamine hypothesis - basically "too little neurotransmitter activity, better beef it up". And so it does! In a matter of days. Any actual antidepressive effect notoriously can take weeks or months, so that obviously isn't the entire mechanism.
No. We don't. While obviously, we know it inhibits serotonin reuptake, we do not know why that SSRI action works. They were developed based on the monoamine hypothesis - basically "too little neurotransmitter activity, better beef it up". And so it does! In a matter of days. Any actual antidepressive effect notoriously can take weeks or months, so that obviously isn't the entire mechanism.
God, that's a book and a half of neuro-interaction, isn't it?