I don't quite track what you mean. I use personal leave for these events (often I don't provide much notice; my brain doesn't either). It's not been a problem so far as I have been told, nor is that a concern I have in my field generally. Being able to take care of things that inevitably fail to fit within the constraints of a weekend is quite beneficial and leads to a lot lower stress levels, which benefits everyone.
Do you tell your employer that you are taking a mental health day, or do you lie an feign some kind of physical illness?
My employer would not respect mental health days by any means. I've taken them before, but I have always faked another illness. I have also always had this overwhelming feeling of guilt and anxiety that if I got caught, I'd be reprimanded.
I usually just say, sometimes earlier in the week, or often the day of, that I'm going to use my personal leave for the afternoon or day, and my supervisor says okay (I've never once been turned down in the almost 8 years I've been here). It's very much emphasized(I've had 3 bosses say this) that my personal leave is for me to use as I see fit, so long as it's done responsibly. For example, if I were taking a week off, I'd let them know probably a month or two in advance, when I started planning. I also have major medical leave separate from my personal leave. I once had to use an entire month(bedridden for 26 days) and it wasn't a problem; I just had to send my doctor's notes to my supervisor once a week while I recovered.