I think some women were treated terribly at home while young by abusive/drunk/physically cruel/absent fathers and are subconsciously trying to re-create that toxic situation. They don't feel 'at home' with a nice, gentle or kind man because they've been programmed to expect and accept bad behaviour. Also, toxic relationships create a level of stress and tension which can be addictive, especially in a depressed person. The 'buzz' of fear or pain is a contrast to the 'deadness' of calm and peace. Also, low self-esteem might mean that these women don't feel they 'deserve' a good man. And finally, there are 'rescuers' who take on lame dogs and strugglers in an attempt to rehabilitate or save them. It seldom works, and the woman wears herself out making excuses for bad, violent, criminal or addictive behaviour. All these situations are ten times worse of course when there are children involved. The only way forward IMO is through therapy and self-knowledge. I saw quite a lot of this sort of thing among the young lassies visiting their men in prison. Many of them were banging their heads on a brick wall, but couldn't see it.