Being in love creates feelings of excitement and attachment, but addicts become overly preoccupied and even obsessed with those feelings. One type of love addiction occurs when a person becomes obsessed with a love interest. These people tend to feel as if they can't live without the person, and that their significant other is their only source of happiness.
Another type of love addiction happens when the addict seeks to replicate the emotional high of a new relationship over and over again. When you're in love, the body releases a bunch of chemicals that make you feel energetic, happy and motivated, such as dopamine. You also have increased levels of oxytocin, which gives you a feeling of attachment. This effect is greater early in a relationship, which is why some people who are "addicted to love" continually seek out new love interests in order to reproduce those early-relationship feelings [source: Sussman].
Scientists think there may be a few things that can lead to an over-preoccupation with love. While brain-related problems or imbalances may be a factor, social interactions and early family life might also play a role. Some researchers even think that our culture's obsession with portraying and idealizing love leads people to become overly focused on it, as well [source: Sussman].