The reality is that both models work together. The amount that each side contributes in a certain individual is dependent on their circumstances and their genetics.
Depression is very much a chemical thing, look into the "comedown" recreational users of ecstasy feel after a night of rolling. MDMA is a stimulant that also excites the same receptors many classic antidepressants work on. MDMA effectively increases the effectiveness of Serotonin and Norepinephrine, the effect on Serotonin is uninhibited and is what causes the "high". After the "dump" of Serotonin into the brain, the brain recalibrates and the baseline Serotonin from before feels like less than it should for a few days. The symptoms are classic anhedonia depression. Clearly an imbalance causes depression.
Depression is also a very situational and mental thing. The traumatic loss of a loved one for example causes deep depression in many people. Even a breakup after a long term relationship can cause deep depression. Therapy and psychoanalysis can help someone become more mindful of their thought patterns. It can push someone to get past the immediate hurdle and regain momentum to live a happy and fulfilling life again.
Neither answer is complete. Trying to find a generic solution is part of what is keeping Psychiatry closer to the blood letting ages of medicine rather than the fMRI scan age.
My personal experience has left me biased and jaded about the current state and future trajectory of Psychiatry and mental health management. Both from the medical professional side as well as from the society side.
It may be a cultural thing, I come from an Asian background and my parents have hung on to that culture. I have stopped bringing up the topic and will excuse myself from conversations when they bring it up because when I try to speak honestly, they treat me like I am trying to peddle narcotics. To them there is only a binary choice, either live drug free and "clean" life or fiend for drugs like an addict. The line isn't based on all drugs in general either, there's a very different stigma around psychoactive vs non-psychoactive drugs. Beta blockers for blood pressure is okay, but beta blockers for performance anxiety and general anxiety is not. I know it comes from a deeper belief system of not taking mental health concerns seriously.
Reading this article was interesting, because I didn't realize western medicine had the same faulty starting point.
I am lucky to have grown up in a time of computer assisted dental x-rays. It's a culture shock knowing how recently Psychiatry was still in the age of lobotomies.
The US still hasn't officially banned lobotomies. The oldest sister of President Kennedy, Rosemary Kennedy was given one in 1941. They continued to be performed officially until the 1970s.
The nobel prize in medicine defends the usefulness of lobotomies and rejects the idea of rescinding the award given to Moniz. https://www.nobelprize.org/prizes/medicine/1949/moniz/articl...