They didn't try to just force themselves to see better.
Ah, but you CAN force yourself to 'think' better.
With physical issues you simply can't do that at all - otherwise we'd all live forever. But I think we have slightly more control over some/many mental issues.
At least I'd like to think that I do - and also that I don't need to rely on meds to get me there.
I don't think so. A clinically depressed person can't just "cheer up." A person with ADHD can't just decide to start paying better attention. These are medical conditions that require treatment the same as arthritis or thyroid problems or asthma do.
There is no shame in getting medical treatment, of any kind, if you need it.