I never claimed to have MDD. My partner had it. He was diagnosed. Also I didn’t say “just changing your mindset is enough", but a mindset of “this will never work I’m doomed forever" will certainly NOT help you recover.
Anyway, major depressive disorder is not only caused by a stroke or brain injury.
It’s also possible to recover from brain injuries even if that was the case — ever heard of neuroplasticity? Not saying every brain injury can be recovered from but the argument that none of them can be is disempowering and plain untrue.