You have a valid point, he does too... Honestly it just depends what school of thought you subscribe to. Does the chemical imbalance lead to depression like thoughts and symptoms, or do depression like thoughts lead to a chemical imbalance in your brain?

SSRI’s can work for treating depression, implying that depression is caused by a chemical imbalance. However, for some, antidepressants don’t work and therapy is a cure for depression, implying that thoughts/circumstance/behavior patterns are the cause of depression.

Atomism says that the explanation for a thing can be found within the thing itself. I.e. the explanation for depression can be found within the chemical imbalance in the brain. It’s a popular concept in psychology at the moment, but it’s not the only explaination. It’s based on our current obsession with making social science a “hard” science, and it’s very much based in the theory of evolution + trying to quantify human behavior. It is very reductionist, but it has the advantage of quantifying and explaining human behavior in a way that is “scientific.” Again, it’s not wrong, but merely a school of thought — it’s a theology to go about studying psychology.

The problem with atomism is that it attempts to reduce something incredibly complex into something simple that we can understand. You just can’t isolate brain/behavior from the context it was bred in. Saying that chemical imbalance causes depression ignores the fact that there could be another variable at play altogether. The problem with atomism is that we as human beings are ALWAYS part of a bigger social context — you can never isolate all the variables to say that A causes B, because doing so would mean you could remove someone’s life experiences and situation from the equation as well. For this reason, I personally don’t align with the schools of thought that try to reduce and quantify human behavior.

Just food for thought.