Continuity mistake: Maria branded Piper on her left arm in season 4. In this episode, the scar is on Piper's right arm.
Chocolate Chip Nookie - S6-E10
Continuity mistake: When the officer is taking Gloria to D-Block because she had a "friend in high places," and she asked where he was taking her, when she's walking down the hall towards D-Block, she's only carrying a small bundle of belongings, but then once it cuts to her entering D-Block, she's now carrying all of her stuff in a much larger bundle. (00:44:00)
Other mistake: The subtitles refer to the men cheering for the female soldier that was stripping as "Marines" despite all of them being in the Army. (00:24:10)
Answer: You would need to be more specific as to which inmate to get an answer as to who possibly belongs in the mental ward. In general; usually the only mentally ill prisoners who go to the mental ward are inmates who show obvious psychotic breaks like Loli and crazy eyes as, with the conditions of prison, it's often difficult to tell who is mentally ill and whose frustrated from the conditions. Many of them are also only there temporarily. Crazy Eyes, first example, was in the mental ward. Her mother fought and won to get her out.