Do you treat the ceiling in your studio?

I have pretty high ceilings. would it benefit to have some treatment directly above myself or the speakers?

absolutely yes
many many details when it comes to acoustically treating a room.
some people say one should start with bass traps, as low frequencies will cause the most problems in the frequency spectrum
i think the least you can do is treating the early reflection points, simply put that means the walls to the left and right, and above your listening position
for some acoustic absorbers to be effective it´s recommended to use a minimum thickness of 10cm
also whether you wanna treat high/mid or low frequencies, you need to pick the right material

might wanna check out gearspace.com - LOTS of great info on acoustic treatment
be patient, if you want to get the best out of your room there´s many things to learn and understand how all this actually works.
again, treating the early reflection points when you can is a good and simple starting point, tho the results may be far from perfect. room acoustics is a rather complex topic