I completely believe in the biological/chemical causes of certain kinds of depression and am by no means anti-med, but very much agree that it is not universal. I think it can actually be straight harmful to treat situational depression with drugs in some cases as they tend to artificially numb the person and that can lead to not processing/dealing with the problem, sinking into avoidance even more etc. Depression is not like a bad tooth or high blood pressure where simply eliminating a simple cause or treating the symptoms can eradicate the problem stably.

I experienced what I am certain was massively chemical imbalance-based major depressive episode and others more tied to life conditions (including my own bad choices) and now thinking back at them, there were big differences in how these different episodes felt and resolved. Just like it is a bad idea to treat a severe major depressive episode simply with talking, the inverse is true for trying to "medicate away" a stressful situation. The latter is exactly what people do when they self-medicate with excessive use of drugs, alcohol and other escaping behaviors.