How Relationships Affect Your Brain

Relationships are an integral part of our lives. They shape the brain in myriad ways (via About My Brain Institute). There have been thousands of songs penned about the drug-like effects of being in love. Being enamored by someone in the early stages of a romantic relationship is often compared to the euphoria of being "high" (via Frontiers in Psychology). Both experiences involve the brain's dopaminergic "reward system," and a spike in neurotransmitters, which is part of why they feel so good.

On the other hand, when friends form a bond or a mother nurtures her child, powerful hormones like oxytocin are released by the brain (via the Annals of the New York Academy of Sciences). This gives rise to feelings of calm, contentment, and security.

Similar to the effects of drugs, sex, love, and even social interactions can become addictive (via Philosophy, Psychiatry, & Psychology). A person may start to feel distracted and uncomfortable when they abstain from satisfying their longing for contact for a long period of time.

Dopamine is another one of the cocktail of chemicals that courses through the brain when you meet someone new (via Philosophy, Psychiatry, & Psychology). This happens when you fall in love. But dopamine is also released during platonic relationships, according to research, such as when you discover a new bff (via the Annals of the New York Academy of Sciences).

Research shows that there are many overlapping neurochemical responses in the brain when people are either falling in love or becoming dependent on an addictive substance (per Philosophy, Psychiatry, & Psychology). The greatest overlap occurs in the region of the brain where dopamine is processed, as well as both oxytocin and serotonin. This may explain why romantic and sexual encounters — and even sometimes certain friendships — can feel addictive.

When a person is love-struck, their nucleus accumbens releases large amounts of dopamine (via Philosophy, Psychiatry, & Psychology). This activates the "reward circuit," also known as the ventral tegmental area — a group of neurons at the very center of the brain — creating a connection between the object of your affection and feelings of pleasure. You feel rewarded whenever you think about or come into contact with that person, as your brain remembers the pleasurable experiences associated with them, and motivates you to seek these experiences out once again.

Even though they feel good, romantic relationships produce chemical changes in the brain that can also make you more stressed out, according to researchers (via ScienceDaily). For instance, when you fall in love, your serotonin levels go down. Serotonin is the brain's "happy" neurotransmitter, which is responsible for regulating mood as well as behaviors like eating and sleeping (via Nutrients). Its decline might explain why people suddenly find themselves feeling restless and on edge, or eating and sleeping erratically when they start falling head over heels for someone.

Interestingly, though, falling in love may affect serotonin levels differently in men and women, according to a study published in the Journal of Psychophysiology. For men, serotonin levels appear to drop in the early days of a new romantic relationship. The female brain, on the other hand, experiences a rise in serotonin. The study also found that women with high levels of serotonin were more likely to become preoccupied by thoughts about their partner.

Research indicates that stress is a common feature of the early phase of love (via the Indian Journal of Endocrinology and Metabolism). In moderate doses, stress sparks the quest for intimacy and closeness, which ultimately helps facilitate bonding. So, you can probably blame those love-anxiety palpitations on the cascade of stress hormones pulsing through your veins.

While dopamine levels are known to shoot up when people fall in love, serotonin goes down (via ScienceDaily). Researchers have suggested that low serotonin levels may be what causes people to have tunnel vision as they get swept up in the initial infatuation stages of a relationship. For instance, it's common to focus your attention on the positive qualities of your partner and overlook the negative attributes. Your concentration can often become foggy and your judgment gets clouded.

"The phrase 'love is blind' is a valid notion because we tend to idealize our partner and see only things that we want to see," Pat Mumby, professor at Loyola University Chicago Stritch School of Medicine (SSOM), told ScienceDaily.

There's also less activation of the frontal cortex when you fall in love (via FEBS letters). This is a brain region that's important in the formation of judgments and executive functioning, which may provide an explanation for why people ignore red flags when they become smitten by someone.

Various chemicals in the brain are responsible for the formation of a romantic bond (via Indian Journal of Endocrinology and Metabolism). Dopamine plays a key contributing role in the development and maintenance of love. And as you enter the later stages of a relationship, your brain releases oxytocin and vasopressin, which help drive attachment.

Known as the "love hormones," oxytocin and vasopressin are produced during sexual activity and orgasm, according to research (via International Journal of Research Publication and Reviews). These neuropeptides are synthesized in the hypothalamus and released from the posterior pituitary gland into the blood (via StatPearls).

Oxytocin is also released in large amounts during childbirth and breastfeeding, promoting maternal attachment (via International Journal of Research Publication and Reviews). This powerful hormone is associated with empathy and trust, and is known to induce feelings of calmness and emotional connectedness. Its presence might account for the shift toward a sense of security and comfort in a relationship as it progresses and deepens (via Indian Journal of Endocrinology and Metabolism).

There's evidence that the different people in your life can change your brain waves. A 2018 study looked at 22 couples aged between 23 and 32 years who had been together for at least 12 months (via PNAS). The researchers discovered that when couples were in the same room together, their brain waves synchronized in a way that was indicative of joint attention. The greatest synchrony occurred when the couples held hands while the female partner was subjected to mild pain on her arm. It appeared that the empathetic touch of a loved one could have analgesic effects for the other.

There might be something to the idea of being on the "same wavelength" as each other. Our brain waves are more likely to synchronize with people that we like and those we spend most of our time with, suggests a 2017 study published in Current Biology. This type of brain-to-brain coupling also correlated with engagement. The researchers observed that the students' brains were more in sync with the classmates they shared their favorite classes with, and were most likely to engage in sustained bouts of joint attention with.

Researchers have long investigated the brain differences in men and women (via Nature). A 2020 study from the journal Science Advances found that brains of men and women respond differently to relationships and social interactions.

The researchers looked at 10,129 brains, both male and female (via Science Advances). Specifically, they examined participants' "social brain atlas," which are the neural regions involved in social behavior and social tasks. They found that these parts of the brain were affected differently by the quality, intensity, and frequency of social exchanges, depending on the participant's gender.

A number of differences were observed (via Science Advances). For example, on average, the ventromedial prefrontal cortex of male participants' who lived in socially stimulating homes was a different volume to those that resided in less social environments. Women with smaller social networks displayed neural differences in their limbic system, which is the brain region tied to behavioral and emotional responses, particularly when it comes to survival, reproduction, and nurturing of the offspring.

However, some researchers object to the idea that men and women's brains are wired differently (via Nature). In a review of the book "The Gendered Brain," Lise Eliot, professor of neuroscience, argues that "modern neuroscientists have identified no decisive, category-defining differences between the brains of men and women."