I’ve practiced psychiatry for a long time, so I have seen the pendulum swing north and south, east and west.
The model that I have always used and that works best for my understanding is a bio-psycho-social model. In other words, we have a genetic/biochemical contribution, a developmental one, and another based on-going life circumstances e.g. loss.
I think the best treatment focuses on all three areas. Recovery depends upon attention to details in all areas of a person's life. Concentrating exclusively on only one of the three areas is never enough.