For me, I found that medication somewhat dulled the pain of cognitive dissonance. After I left bethel, the pain just got worse as I got to know lots of "worldly people"... very good and nice people that would never wish me any harm... yet my religion was teaching me that they all deserved to die horrible deaths so I could have a pet panda.
After I stopped attending meetings, that mental pain started to clear. Now that I have my degree and a great job, life is completely different.
I don't think I was medicated for a mental illness, it was all to dull the pain of the WT belief system.