The neuroscience of breakups

“It’s better to be single with a standard than to lose me for your approval.” Breakups are never easy for most people. Here, I will start with the neuroscience of breakups, and enrich the understanding of breakups emotions through animal models. I will contrast the knowledge with current societal perception and provide mental health suggestions to assist individuals through breakups.

Neuroscience of breakups

Reward pathway

The brain area related to dopamine and pleasure, the reward pathway, is still active even after the breakups. In Fisher’s (2010) experiments, subjects who are still in love after the breakups are instructed to look at the photos of their love rejector with distraction-attention tasks. They showed more activation in the midbrain area of ventral tegmental area (VTA), bilaterally, ventral striatum, medial and lateral orbitofrontal, and cingulate gyrus.

This pathway connects VTA in the midbrain to the nucleus accumbens in the basal ganglia. VTA involves feelings of romantic love, while nucleus accumbens involves motivation and action. When VTA is activated, VTA dopamine neurons will be projected to the nucleus accumbens. Hence, the dopamine level in the nucleus accumbens rises, contributing to wanting, craving, and addiction (Feltenstein & See, 2008). The circuit is produced via the dopamine reuptake recept transporter (DAT) blockade in the pathway. Adversity or breakups can even strengthen the feelings of romantic love because when the reward is delayed, the dopamine neurons will continue their activity (Fisher 2004; Schultz, 2000). It concludes that the reward system prolongs whether their relationship status is satisfying or not, which might explain why people rebound after a toxic relationship.

Figure 1. The reward pathway from VTA to nucleus accumbens

Addiction

Often, if the nucleus accumbens is paired with drugs, it can cause addiction (Cardinal & Everitt 2004). Research shows that craving reflects a pattern of brain activation as people gain stimulus and repeat similar activities in romantic relationships. Cocaine-induced euphoria and cocaine-induced craving are associated with the reward pathway (Breiter et al., 1997).

To cause addiction, the reinforcement of drug usage, and romantic behaviors draw similarities. In contrast to substance abuse, romantic love addiction is formed by hedonic experience. As a person constantly seeks physical intimacy, attention, or being in the same physical space, it creates a pattern of behaviors and dopamine rewards(Sussman, 2010; Cardinal & Everitt, 2004). If the incentive level is high, the behavior comes from habitual to even compulsive, which can be related to the offending and substance abuse after breakups (Larson & Sweeten, 2012).

Grief

Grief is a primary emotion after the breakups too. For fMRI brain scan results, Najib et al. (2004) use acute grief, grief minus neutral state, as measurement, and find that cerebellum, anterior temporal cortex, insula, anterior cingulate, and prefrontal cortex activities change when researchers ask subjects to change between neutral thought and ruminating their loved one. Those regions, especially insular cortex regions and anterior cingulate, are associated with physical pain (Fisher et al., 2010).

Besides, the nucleus accumbens also positively correlates with the self-report yearning when recalling the death of their loved ones (O’Connor et al., 2008).

Survey analysis shows similar results as the brain scan. Through the Grief Experience Inventory (GEI) and Texas Revised Inventory of Grief (TRIG) questionnaire, the more intimate a relationship is, the more grief occurs without much gender differences. If the breakup is initiated by someone else, subjects experience more grief and a stronger loss of control (Field et al, 2009).

Emotional control

The brain area regulating emotions is also activated because of the conflicting and desperate feelings. Research shows that the orbitofrontal cortex and ventrolateral prefrontal cortex are activated for emotional learning, behavior control, and cognitive reappraisal. Successful cognitive reappraisal can reduce negative emotions (Wager et al., 2008).

Animal behavior for partner loss

The research separates 79 female and male prairie voles, monogamous rodents, into two groups based on their partner preferences. Half of the males in each group are separated from their partner(the loss group), while the other half isn’t (the paired group). Several experiments are conducted to evaluate anxiety and stress for separation.

The researchers first pair up males and females for 7 days. After the pair bonding, they conduct a partner preference test (PPT) by creating three chambers, partner, neutral, and stranger chambers, and video male rodents’ behaviors, such as staying in the female’s chamber, huddling with or licking the fur of the female. They use PPT to separate the males into a bonded and unbonded group. Afterward, they conduct three tests: open field, plantar, and formalin test. All the results are insignificant for the unbonded group, which doesn’t have partner preference. In contrast, the bonded group shows a difference.

For open field tests, the paired and loss group is put in a square container, and their movements are recorded. It shows that the bonded paired group travel significantly longer than the bonded loss group. The bonded paired group is much more likely to stay in the center than the edges, indicating less anxious behavior (Carola et al., 2002).

Figure 2. A more anxious rate behavior(left) vs. less anxious rate for open field tests

For the plantar test, researchers measure hind paw withdrawal latency from radiant heat. They see that bonded loss males displayed shorter withdrawal latencies, meaning more nociception and anxiety (Kremer et al., 2020).

For the formalin test, researchers inject 5% formalin into rodents’ paws to measure nociceptive behaviors. They observe that though group differences don’t exist for licking the paws, bonded loss males lifted their paws much more frequently.

Figure 3. Formalin test potential result. 0 paws before injection, 1 injected paw has little effect, 2 injected paw is lifted, 3 injected paw is licked.

The experiment shows that the bonded loss group has a more anxious and painful behavior. Since anxiety is a behavior of grief in rodents, the experiment might inform the grief of losing someone after breakups (Demarchi et al., 2021).

However, the interpretation remains indirect:

1. Even though rodents are divided into two groups based on their partner preference, they aren’t actively given a choice to separate, while breakups might do.
2. The motivation for initiating breakups might have already introduced some confounding variables, such as unhealthy communication, different expectations, and unresolved problems in the relationships, let alone when those variables combine and interact.
3. After the male rodents are separated, they experience complete social isolation. At the same time, humans might seek a friend and family support after the breakups.

A proposed study can be placing the loss group into a social environment or not and evaluating the anxiety and pain behavior. For instance, if a bonded loss rodent is placed in a familiar social group, how would it behave compared to other bonded loss rodents and the not bonded rodents? The gap between the three groups might provide helpful knowledge of the effects of friends and family. Despite all the limitations above, it still informs us that the intense negative emotions after partner separation are natural among mammals.

The societal perception

Larson (2016) found that romantic breakups have a significant contribution to crime for adolescents due to a decrease in psychosocial characteristics and peer associations. Even though pair-bonding plays a crucial role in evolution, and pain and negative effects of breakups are observed in both humans and animals, the current society hasn’t taken the negative effects of breakups seriously and provides adequate assistance.

One potential reason is that the current society values rationality, productivity, and independence which de-emphasize the importance of emotions and romance. Grieving over breakups seems to be a personal matter and a time-wasting act. The societal perception of addiction can also overlook the severity of breakups. Due to the stigma of addiction and the perception that romantic love is positive, current society doesn’t classify romantic love as addiction, let alone establish a mental health process to treat the heartbroken “addicts.” While research (from above) suggests that love can be addictive by stimulating the reward pathway, the stigma relates to unhealthy breakups behaviors, such as denial, drinking, withdrawal of support, or even breakup revenge (John, 2017; Larson & Sweeten, 2012). Due to the scope of this writing, we will not focus on addressing the social perception of addiction and breakups, but on individuals’ actionable items after experiencing breakups.

Individual Mental Health

Post relationships grief includes both physical and emotional trauma. From a survey, negative emotional effects, such as anger, depression, and anxiety are reported by 98% of participants, while physical effects, such as nausea, sleep loss, and weight loss, are reported by 93% of participants after they break up (Morris, & Reiber, 2011).

Since addiction will decrease satisfaction with other rewards, it’s challenging to establish new routines and reward systems. Here are several suggestions for some positive changes an individual can make.

1. Discard all the sources related to the ex, including photos and letters, so there are fewer environmental cues to trigger the craving.
2. Positive interpretation and acceptance will foster positive emotions and growth. People describe themselves as becoming more goal-oriented and learning a lot about themselves when they process the breakup through a positive lens (Lewandowski & Bizzoco, 2007). Writing about positive feelings compared to negative and neutral feelings also increases positive emotions, showing the possible effects of cognitive reappraisal (Lewandowski, 2009).
3. Exercise can elevate mood and decrease anxiety, and reduce the risk of depression after the trauma (Hansen, 1998; Chen et al., 2020)
4. Self-expansion activities, such as meditation, might have a positive effect. Long-term mediation reduces anxiety and negative emotions, while short term can mitigate the increase of anxiety (Sears & Kraus, 2009).
5. Social support from friends and family, especially in-person conversation, benefits personal growth much more than calling and texting in the Post-Traumatic Growth Inventory survey (Choi & Toma, 2017).
6. Therapy is a general good practice for mental health. Having a professional can guide individuals through self-growth and positive actions.

p.s. Studying this hardcore neuroscience is a joyful and calming process that takes away the fear of my emotional tsunami and unpredictable behavior after the breakup. As the research shows, a positive mindset encourages growth 😉