No-one has.
You just did. By claiming that depression is not in your head.
Depression is a mental disorder and by the virtue of being a mental disorder is, quite literally, in your head.
“Objectively, it’s JUST in your head.”
You said something moronic which I’ve proved completely wrong and instead of manning up and taking your words back, you dig in deeper to your stupidity, as if this was real life and you could get away with your bullshit.
You don’t know a single thing about psychiatry, child.
Edit and also digestive issues are very much commonplace in mental disorders and poor nutrition can cause depression and in depression your entire body gets inflamed, so one could actually say depression is also in your arse