Most prisoners who stay in Solitary Confinement for long periods of time go insane and I can see why.
Imagine being locked in the prison cell with absolutely nothing in there but your toilet, bed, sink etc with basically nothing to do and no window to the outside world and imagine having to stay in that cell for 23 to 24 hours per day.
That would cause you to lose your mind.
As an example have someone lock you in your bathroom for a few days and you'll likely go insane too.
Solitary confinement just makes dangerous people even more dangerous and does nothing to help them.
I was once locked in the bathroom of a rest stop on a long stretch of highway where there was no one else but me for nearly an hour until someone came and got me out after I called 911 and told them where I was.
There was no quick way for anyone to get there because the rest stop was a long ways from any towns or cities.
I was about to go insane even though I knew help was on the way and I would be out of there and at least I had my android phone with internet access to keep me occupied while prisoners have nothing to keep them occupied.
I didn't really lock the door but for some reason it didn't want to open but they somehow got me out.