Not all cheaters are sociopaths and not all sociopaths cheat.  However, there is a good  bit of overlap.  LoveFraud.com is geared toward educating people (women and men) about how to understand and deal with sociopaths.  The website's head honcho, Donna Anderson, is an expert on this topic.  Here is the link to an excellent, recent article of hers:

http://www.lovefraud.com/2015/12/21/10-signs-youre-addicted-to-loving-a-cheater-2/