I have a post in progress that has required an unexpcted amount of time and research. Hence, you will find very many references, which took considerable time to find, retrieve, and read.
The subject is a causal link between major depression and antisocial personality, the latter of which, previous to DSM IV, had been referred to as sociopathy or psychopathy. Essentially, the severely depressed should display antisocial behaviors.
I hope to complete this post soon. I will complete it within the next week, if time allows.