Factual error: Whenever Tiffany gets her dentures there's one problem. She's got her hands cuffed in front and prisoners, unless they're cuffed to the waist and ankles too, should have her hands cuffed behind her back.
Take a Break from Your Values - S2-E11
Continuity mistake: When Piper calls Alex she is drinking wine till the glass is empty but in the next shot the glass refills by itself.
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.