You misread what I wrote, and then got angry about what you imagined I wrote. Usually I don't explain myself to strangers on the internet, since people who angrily misread also usually angrily double down, but here goes.
In the US, it is frowned upon to take a scheduled day off just to relax, outside of your annual 2 weeks of vacation. So you call in "sick". Since you're not really sick, but want to relax, you call your reason for illness a "mental health day". I characterized this practice as cutesy, because it's a cutsey repurpose of the concept of sick day for self-care. It's not a mental health crisis, it's relaxing. But as long as you characterize it that way, it gets a nod and a wink from anyone who cares.
In Europe, by contrast, if you need time off because work is stressful, you plan ahead, take the day off and be cheerfully honest that you spent the day at the beach or whatever. But if you tell people you were sick, and then spend the day at the beach, people will at best think you are odd, but probably will think you're a liar. Telling people it was a "mental health break" to call in sick in order to go to the beach will not get the same cozy reception it gets in the US.
Clear?
If I am anxious or depressed, going outside into nature or to the beach would help me tremendously. Much more so than sitting at home. How anxious and depressed do I have to be before it flips from "relaxing" to "legit"?
At my job I get x vacation days and y sick days. If I feel I unwell mentally I am going to use a sick day. Why is it anyone's business why I am sick or what I did on my sick day?
If my coworker said they were feeling terrible yesterday so they took the day off to go to the beach I would understand and encourage that. I would also admire them being brave enough to admit that rather than pretend they had a virus.
> If I am anxious or depressed, going outside into nature or to the beach would help me tremendously.
If you are feeling that semi regularly, you might be on your way to a burnout or actually experiencing one.
Advertising 20 days + public holidays in the UK is basically advertising that you give people the minimum the law will let you.
That's why it's such a breach of trust here to take a sick day in order to relax. A sick day is to recover from illness.
In Europe, calling in sick when you're not actually, recognizably ill is a pretty serious breach of trust. No cutesy "mental health break" exceptions. That said, you likely have at least 20 days of paid vacation, plus holidays.
In the US, where 10 days paid vacation is the norm and you're often punished in some way for actually taking it, the occasional "mental health break" of calling in sick is winked at.