It's not so much that the modeling of the brain is flawed; it's just that the chemistry of stress and recovery in our brains is complex and has multiple variabl

It's not so much that the modeling of the brain is flawed; it's just that the chemistry of stress and recovery in our brains is complex and has multiple variables. There are lot of outstanding questions. There are different kinds of depression that manifest themselves with different symptoms (manic depression, sluggishness, suicidal thoughts). What causes some but not others? The type of treatment can depend on this. Serotonin plays a big role in depression, which helps explain why SSRIs are so effective. Dut is depression caused by not enough serotonin, or is it because the receptors aren't as sensitive to it? Norepinphrine is used by the locus coeruleus, and a lack of it has been linked with PTSD, panic disorders, and depression. Why doesn't this new medication make a difference? Are the low levels of norepineprine a cause or just a symptom? Dopamine signals the pleasure pathway. A lack of it means a lack of pleasure, which is definitely a part of depression. Those are the big three chemicals, but there are so many other variables. There's a genetic component to depression as well. What genes are responsible for hereditary depression? Even if you inherit the gene, it may require some environmental stimulus to cause it to express itself. What sort of role does childhood trauma play with this? If you're interested in this stuff, read "Why Zebras Don't Get Ulcers" by Robert Sapolsky. It's a really well-written, thoroughly researched book on stress and anxiety from a scientific perspective. The writing is approachable without pandering, and having a bit more insight into the science of our weird little happy/normal/sad system has given me some direction in managing stress in my life.