I think you’re throwing the baby out with the bath water here. Sure depression may not be linked to low serotonin levels but it almost certainly some chemical imbalance of some variety.
Drowning or having your leg cut off leads to a chemical imbalance, but chemistry isn't always the most productive lens to analyze the problem
Thats the basically the point I am taking issue with. Myopic focus on chemistry can be terribly misleading. There will always be a chemical component because we are beings made up of chemical components.
a chemical imbalance is by definition always going to be part of the problem. That does not mean it is always the best point of intervention, and certainly not the exclusive focus when trying to understand the problem.
If your only tool is a hammer then every problem looks like a nail.
The brain is a lot more than chemistry, and that's not even looking at the human being and their interactions with the environment.
there are patterns encoded in the structure and biology of the brain. There are psychological feedback loops and complicated interactions between a human and their environment.
Saying it must be a chemical imbalance is akin to debugging a malfunctioning computer and saying it must be a signal error from a loose wire. It ignores programming sending signals on those wires and it ignores the input to the machine from the environment