Answering the question of why does coping with these pressures take this form does indeed have a biological component. It’s not excuse making to ask why humans respond to certain negative pressures in a recognizable pattern.
https://www.nationalgeographic.com/science/article/nick-cage...
Point being, all we have is correlation, and to go down the road of chemical imbalance can lead to wasting time, more people socially withdrawing, and possibly more people being harmed by some cockamamie medical treatment for something that may very well be socially instigated.
And what better way to dismiss people's problems than to assume they're defective.