I disagree. We know very well how neurons work, and we have a pretty good idea of how neural activity translates to behavior. In other words, we have a pretty good idea on how the brain works. We stop at consciousness because as of yet it is in the realm of philosophy, not science. We don‘t know what consciousness is or even whether or not it is useful for science and we are simply waiting for the philosophers guides us out of that situation.
Note that both cognitive psychology and behavioral psychology has done fine without tackling consciousness. When neuropsychology emerged in the 1980s it complemented both these fields perfectly. The situation is the opposite with the philosophy of mind which grew significantly around the same time.
There have been some attempts to describe consciousness as an emerging phenomena out of neural activity, but so far all of these attempts have failed, or at least failed to turn consciousness into a useful term in psychology (the way gravity is a useful term in physics). I think it is equally likely that these attempts have failed because consciousness may simply not be a useful term in psychology, that is as likely as it is that we simply don‘t understand it well enough.
We know how neurons fire. We do not know how a brain turns that into thought, meaning, intention, experience and on and on. That is not "pretty well understanding the brain", it's understanding some components and hand waving the thing we actually care about.
I feel like the search for consciousness is to psychology what the search for the Aether was for physics and chemistry. I think it is a worthwhile search, and maybe we will discover something important during that search, but we should also be prepared to find out that the thing might not exist, or it’s presumed properties are better explained with a different model.
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.