I've always been suspicious of people who talk about "psycho girlfriends" or ex-girlfriends. Most often, their behaviour seems to be a reaction to dickish men. And strangely, since it is more likely to be men that are truly "psycho" (and please note, this is not a word I ever use personally, due to its negative connotations for people with mental health issues), men seem to escape this label, no matter what sort of harm they cause to their girlfriends or wives.
The "psycho girlfriend" seems to be another unjust way of putting women down and making the whole gender seem unhinged. In my experience, it is almost exclusively due to men's lack of bravery when ending a relationship. The accusation was levelled at me on one occasion when I sent a couple of text messages to a guy who had suddenly and inexplicably cut contact. If he had simply had the guts to tell me he didn't want to see me again, I would have let it go.
And why is it that constant phonecalls, gifts, over-attention etc. are hallmarks of the "psycho girlfriend" but also of the romantic, attentive boyfriend?