When the love of your life dumps you, you’re going to go a little nuts. But it’s a very specific form of crazy: There are actually conflicting neural systems active inside your brain. It’s like you’re falling in love all over again, only in reverse. Here’s how neuroscience explains it.


Addicted to Love

It doesn’t matter whether you were with your ex-lover for six months, four years, or more – a breakup throws your brain back into the obsession of early love. Everything that reminds you of that person – a photograph, places you used to go together, random thoughts – triggers activity in “reward” neurons inside the caudate nucleus and the ventral tegmental area of the brain. These are the same parts of the brain that light up when scientists put people in the throes of that grossly cute can’t-think-about-anything-else stage of new love into an fMRI machine and ask them to look at photos of their beloved. As it happens, they’re also parts of the brain that respond to cocaine and nicotine.


Turning on the reward neurons releases repeated floods of the neurotransmitter dopamine. And the dopamine activates circuits inside the brain that create a craving for more. That craving gives you motivation, and encourages you to try out other behaviors that will help you get more of whatever it is you need. In the case of romance, the thing you need more of is your beloved.

As a romantic relationship develops into a long term partnership, that obsession fades away, even though thoughts of your partner still tickle the brain’s reward systems. But after a breakup, all those old can’t-get-enough feelings come flooding back. The brain’s reward systems are still expecting their romantic ‘fix’, but they’re not getting the responses they expect. And like someone in the depths of a drug addiction, they turn up the volume in an effort to get you to respond.

In this new context, the reward system is now the part of your brain that’s going to motivate you do something really dumb. Like drunk calling your ex, or initiating breakup sex.

Lucy Brown, a neuroscientist at Einstein College of Medicine who has studied romantic responses in the brain, explains that the motivation is more extreme than for other forms of social rejection because romance ties into more primal parts of the brain. “Other kinds of social rejection are much more cognitive,” she says. “[Romantic rejection] is a life changing thing, and involves systems that are at the same level as feeling hungry or thirsty.”


No wonder it hurts.

The Pain is Real

When your lover leaves you, chances are you’re going to feel it. Your chest gets tight, you feel sick to your stomach, or maybe there’s that sinking sensation that accompanies terrible news. Two studies that looked at brain activity inside people who were deep in the throes of a breakup found that the reward regions weren’t the only systems lit up inside their brains. They also saw activity in brain regions that control distress and the response to physical pain. Specifically, the parts of the brain that collect pain sensations from the outside world were quiet, but the systems they tie to–the systems that control how the body reacts to pain–were busy telling the body that something awful was happening.


And since the brain controls the body, turning on those systems can trigger a cascade of effects: for example, releasing stress hormones which in turn affect the heart, the digestive system, even the immune system. In some extreme cases, the stress can make the heart weaken and bulge, creating a condition called takotsubo cardiomyopathy or “broken heart syndrome,” which can sometimes lead to death.

Fortunately, those sorts of extreme stress responses are rare. But the pain of a romantic rejection can still last a long time. There’s a lot of variation from one person to the next, but Brown says the painful feelings usually fade away over the course of about six months to two years. But the pain is a natural part of the process. Breakups hurt because they turn on a basic system that gets us to make and maintain meaningful connections with other people. “It’s a system to try to keep us together”, Brown explains. “When we have little separations, these feelings get us to work hard to get close to the person again. If two people are cooperating, it works.” When they’re not, it’s as much of a hurt as a cut or a broken bone.


What Were They Thinking? And What Can You Do?

So far, all the “breakup fMRI” experiments have looked at brain activity in dump-ees. Like you, science still has no idea what’s going on in the brain of a dump-er. Logic suggests there must be some mechanism that can slowly erode and weaken connections in the brain’s attachment pathways. We do know that neural connections that aren’t used in sensory pathways can get pruned away, so perhaps this type of neural rewriting can also slowly change the way your lover feels about you until one day, those warm feelings of romantic attachment are gone.


And then comes that “We have to talk” visit.

But when you’re heartbroken, there’s no reason that you can’t try things that encourage your brain to rewire itself. In fact, there’s evidence that immediately after a breakup your brain is working hard to get you to move on. Those same brain scans of the heartbroken that showed their brains were awash in pain and desire also had activity in regions of the frontal cortex that inhibit impulses and redirect behavior.


In short, explains Brown, your brain is trying to regulate your mixed-up emotions, prevent you from doing at least some of the crazy things you feel compelled to try, and help you start putting your life back together. It will take time to get over it. But over time, the brain activity of romantic obsession will go away. Until then, Brown suggests trying a little memory rewriting of your own. “When the thought of that person comes up, instead of thinking how great [the relationship] was, think about how bad that person was for you instead.”

[Mearns 1991 | Aron et al. 2005 | Wittstein et al. 2005 | Smith and Vale 2006 | Acevedo et al. 2010 | Fisher et al. 2010 | Kross et al. 2011 | Cooper et al. 2014 | Eisenberger 2015]


Illustration by Jim Cooke

Contact the author at diane@io9.com .