Respectfully, you are miles out of your depth here.
My point with the SSRI is that we know that serotonin is a chemical which incites certain neurons, and we know that a lack of activity of neurons in that general area in the brain is correlated with depression, so scientists were able to accurately predict that keeping the serotonin in that brain area for longer would increase brain activity there and decrease the level of depression.
This counts as pretty good understanding in my books at least. It teaches us very little about consciousness but my point is that it doesn’t have to. Just like Newton’s theory of gravity did not have to teach us about some deeper cosmological truth.