This doesn't really surprise me. Women with mental, emotional and behavioral challenges are overall very vulnerable to sexual and physical abuse. This is not only because it is often easy to take advantage of them and get away with it (they are often dismissed as 'crazy', or find it difficult to articulate what has happened to them) but because their erratic behavior can be difficult to deal with, and might be more likely to trigger violence against them from others who are easy angered or frustrated and express that in bad ways.