Using a z isn't necessarily incorrect for British English, as it's actually fairly common over here. If you look at some online UK dictionaries, they'll usually use the z version and footnote or side mention the s spelling as also common.

Couldn't reply to your other post for some reason, but I'm so sorry to hear what you're going through right now. Always here if you need someone to talk to, you're not alone 🫂

Meds did nothing for me, but no quantity of the outdoors, nature or pets seem to ever entirely solve it for me, so it's just something I forever struggle with. For someone else in my family meds help them tremendously and without them they're barely functional.

Depression is unfortunately complex.