There are bell curves of pretty much every human characteristic. When someone is at the far end of the bell curve in a way that negatively effects their interaction with the majority of humans that are in the bulk of the bell curve, we call it a disease. In the case of depression, deviations from the norm in that characteristic have a chemical basis. It's not victim blaming to point this out.
That doesn't mean we don't need to be sensitive to people with circumstances that deviate from the norm. At the same time, our expectations of how we should treat people are calibrated to the typical responses of people in the bulk of that bell curve. It is regrettable but not necessarily wrong when those expectations conflict with the needs of someone who lies outside that region of normalcy. We owe everyone common decency, but we don't necessarily owe anyone uncommon decency.
This is well-put. What I often wish is that there was a different word for these "end of the bell curve" problems; lumping them together with diseases caused by actual pathogens is, I feel, what can cause some of the skepticism about them being "real," because they are clearly not real in the same way that HIV is.
Having a clear classification would acknowledge that we know there's a difference, but that we still regard non-infectious disorders as very serious because they can be equally awful in their own ways, and they can sometimes respond to medical treatment.
That doesn't mean we don't need to be sensitive to people with circumstances that deviate from the norm. At the same time, our expectations of how we should treat people are calibrated to the typical responses of people in the bulk of that bell curve. It is regrettable but not necessarily wrong when those expectations conflict with the needs of someone who lies outside that region of normalcy. We owe everyone common decency, but we don't necessarily owe anyone uncommon decency.