If a prisoner is only in Solitary Confinement for a few hours to a few days then it's easier for the inmate to stay sane if they know they'll be getting out of Solitary confinement soon.
But most inmates who stay in Solitary Confinement lose their sanity after a few days in Solitary Confinement especially if they're in there for months or even years at a time.
After a few days of being in Solitary confinement some inmates will cut their wrists etc so that they will be removed from the solitary confinement cell and some even do it to commit suicide.
I can imagine the torture and being stuck inside a small room with no windows for awhile with nothing to do.
When I was 15 I got locked inside of a bathroom in a small gas station and the bathroom had no windows and I was in the locked bathroom for 1 hour until the owners of the gas station found me and got some help.
I was about to go insane locked in that bathroom with just a toilet and sink and no view to the outside and I was only in there for an hour.
Now I have a fear of locking the bathroom doors on small bathrooms with no windows.