I used to react strongly to antihistamines, even weak ones, that are not supposed to induce sleep (levocetirizine would knock me off), but after mirtazapine I g

I used to react strongly to antihistamines, even weak ones, that are not supposed to induce sleep (levocetirizine would knock me off), but after mirtazapine I got a semi-permanent tolerance to other antihistamines sleep inducing properties -- so if other antihistamines cause dementia, I'd expect mirtazapine to do so as well. It's also a pity because I used to feel quite well rested and clear headed the day after antihistamines.