Why DE's may have not gone mad

[rosabella_rb]

No: HPFGUIDX 80088

In response to Eligro2000, I think that perhaps the only thing that 
may keep someone from going insane in Azkaban is holding off to a 
thought that is not terrible yet not happy, something that the 
Dementors cannot suck out. Sirius says in PoA that the one thought 
that kept him sane was that he knew he was innocent. I don't know 
about the others, but perhaps Bellatrix retained her sanity because 
she had hope that one day Voldemort would come back; she was proud of 
her loyalty; perhaps she even was so sure she was eventually going to 
get out that she summoned the will to block any happy memories - 
perhaps most prisoners go mad because they know they have little or 
no chance of leaving and to top off the Dementors?

I had another thought, though: would a highly skilled Occlumens be 
able to block his happy memories so that the Dementors couldn't get 
them? 

"rosabella_rb"