I'm not really sure my experiences are as relevant since my psychosis was likely drug-induced but...

During my first period of psychosis I was convinced people were watching me, largely thanks to my voices telling me they were. I would look behind me when walking outside, cross the street or walk a different way home to avoid people following me. I also regularly checked for cameras & was changing my passwords for various things every few days.

That probably went on for a month but started subsiding. I didn't actually go on medication for another 6 months after that by which time it was just vague feelings of being watched. Nonetheless, the medication totally cleared all thoughts of being watched.

Second time around my feelings of being watched weren't as pronounced but were more persistent. Again though, when I went on meds they went away pretty quickly.

It seems to me meds are particularly effective at controlling my paranoia/delusions but less so for voices. I've always heard voices even when I've been on high doses of medication. So latterly I've chosen to stay on low doses not trying to get rid of the voices to minimize side effects from APs. I'm now actually off APs altogether but still hear quiet voices.

Just a guess, but I think Atypical Antipsychotics...