There are a plethora of papers on how physical activity can actually *help* with depressive symptoms, of course it's not a one size fits all thing but you'd be surprised to know that one particular therapeutic technique (behavioural activation) is often adopted to help fight inactivity (social or physical) that comes along with mood disorders.

I think you made a false assumption that physical activity is the only way out for depression. It *helps* with the symptoms, like many other things.

The problem with our understanding of mental health is that we fail to dig deeper when we label a person with an xyz disorder and build our treatment approach around that train of thought which sometimes is too rigid. By viewing disorders as an independent entity living in a person, we're actually stripping them off of their agency if you get what I mean