It is in a part of Derby that I personally wouldn't be walking around after dark. I think it is the combination of the area and the almost non-existant train service, so there won't be any passengers around whose presence might discourage any anti-social behaviour.
I'm not going to pretend Peartree is the best area of Derby, but by national standards it's not that bad.
There are much worse areas in bigger cities. But possibly those stations are busier.