Love is like cocaine: The remarkable, terrifying neuroscience of romance

On popular websites, we read headlines such as “Scientists are finding that love really is a chemical addiction between people.” Love, of course, is not literally a chemical addiction. It’s a drive perhaps, or a feeling or an emotion, but not a chemical addiction or even a chemical state. Nonetheless, romantic love, no doubt, often has a distinct physiological, bodily, and chemical profile. When you fall in love, your body chemicals go haywire. The exciting, scary, almost paranormal and unpredictable elements of love stem, in part, from hyper-stimulation of the limbic brain’s fear center known as the amygdala. It’s a tiny, almond-shaped brain region in the temporal lobe on the side of your head. In terms of evolutionary history, this brain region is old. It developed millions of years before the neocortex, the part of the brain responsible for logical thought and reasoning.

While it has numerous biological functions, the prime role of the amagdala is to process negative emotional stimuli. Significant changes to normal amygdala activation are associated with serious psychological disorders. For example, human schizophrenics have significantly less activation in the amygdala and the memory system (the hippocampus), which is due to a substantial reduction in the size of these areas. People with depression, anxiety, and attachment insecurity, on the other hand, have significantly increased blood flow in the amygdala and memory system.

Neuroscientist Justin Feinstein and his colleagues (2010) studied a woman whose amygdala was destroyed after a rare brain condition. They exposed her to pictures of spiders and snakes, took her on a tour of the world’s scariest haunted house, and had her take notes about her emotional state when she heard a beep from a random beeper that had been attached to her. After three months of investigation, the researchers concluded that the woman could not experience fear. This is very good evidence for the idea that the amygdala is the main center for fear processing. (The chief competing hypothesis is that fear is processed in a brain region that receives its main information from the amygdala.)

Despite its tiny size, the amygdala is amazingly powerful. When its neurons fire intensely, this triggers a physical stress response in your body. Hans Selye, a Canadian endocrinologist, was the first to apply the word “stress” to physical and emotional strain. Before that, “stress” was just an engineering term. Selye, who did the bulk of his research in the 1930s, discovered that the stress hormone cortisol had detrimental health effects in rats.

Together with other adrenal gland hormones, such as epinephrine (adrenaline) and norepinephrine (noradrenaline), cortisol prepares the body for a “fight or flight” response. Stress hormones are secreted in situations of perceived danger. They can be aggressively rushing through the bloodstream, even when the danger isn’t real. For example, they run rampant in people with a fear of public speaking. They make your heart breakdance, your skeleton turn to gelatin, and your new Mickey Mouse voice make little squeaks the first time you stand in front of a hundred-person audience.

Falling in love then goes like this. Unpredictability, mystery, and sexual attraction make the amygdala go into a hyper-activation mode. Via neurotransmitters, this signals to the adrenal glands that something exciting, scary, mysterious, and unpredictable is going on. This, in turn, results in the adrenal glands pumping a surge of adrenaline, noradrenaline, and cortisol into the bloodstream. Via the bloodstream, adrenaline increases heart and breathing rates; noradrenaline produces body heat, making you sweat; and cortisol provides extra energ y for muscles to use.

Though falling in love is associated with anxiety and stress, this state—in combination with the belief that there may be reciprocation—is also at times accompanied by intensely pleasant emotions. These emotions arise from an underlying brain chemistry that resembles those triggered by cocaine use.

Your Brain on Crack

Cocaine is a serotonin/norepinephrine/dopamine reuptake inhibitor, like the most frequently prescribed antidepressants. Serotonin reuptake inhibitors block the transporter that normally carries the “feel good” neurotransmitter serotonin into the neurons. When serotonin is inside the neurons, it does not function as a neurotransmitter. To have an impact on the brain, it must be extracellular, or outside the neurons. When the transporter is blocked, less serotonin is carried back into the cell. So, the extracellular levels of serotonin increase, which stabilizes the brain’s chemistry and alleviates anxiety and depression.

Cocaine increases the brain levels of serotonin, norepinephrine, and dopamine. But unlike the selective serotonin reuptake inhibitors, or SSRIs, doctors normally prescribe for depression (for example, Zoloft, Celexa, or Lexapro), cocaine works instantly. This is because cocaine is a much more potent drug. Whereas standard antidepressants only partially block neurotransporters, cocaine completely blocks them, giving rise to a steep peak in the levels of norepinephrine, dopamine, and serotonin.

Because dopamine is associated with pleasure and memory associations between certain actions and pleasure, stimulants and narcotic drugs that increase the brain’s levels of dopamine can cause addiction. The brain remembers the intense pleasure and wants it repeated. This, however, is probably not the whole story behind addiction. Though pleasurable or satisfying activities normally are necessary to initiate an addiction, it may be an overall less efficient pleasure response to ordinary events that causes addiction. It’s the pleasurable or satisfying feeling created by dopamine that entices us to try a drug a second time. But it is likely a dopamine deficiency, a smaller number of dopamine receptors, or an impairment of the function of dopamine that causes addiction. For people with an addictive personality, normal everyday activities, such as working, reading, or watching a movie, don’t lead to sufficiently intense pleasure, so they seek the drug to give them a more profound experience.

Over time, cocaine and other drug use desensitizes the brain to the drug. Desensitization happens as a result of an increased reuptake of the drug or a reduction in or desensitization of receptors. As a result, a larger amount of the drug is required to achieve the same stimulating effect.

New love can have similar effects on the brain as cocaine. Helen Fisher, an anthropologist and relationship researcher, conducted a series of fascinating brain imaging studies of the brain chemistry and brain structure underlying new love. She found that serotonin, dopamine, and norepinephrine are crucially involved in the initial stages of romantic love in much the same way as they are in cocaine use.

Beliefs and Brain Chemistry

When the systems of neurotransmitters in our brain destabilize during the early phases of a romantic relationship, our moods become unsteady too. And so does our ability to think rationally and make wise decisions. When you become truly infatuated with a person, you might make decisions you wouldn’t dream of making in a sane state of mind. Nothing really matters compared to the object of your infatuation. In extreme cases, we might max out credit cards, leave our families, move across oceans, abdicate a throne, rob banks, or even commit murder for the sake of love.

When there is a substantial imbalance in your brain chemistry, your preferences and reasoning abilities change and so do your beliefs. Research has shown that when you mess with your brain chemistry, you are more likely to have spiritual experiences, see things that are not there, and form beliefs that are not grounded in evidence.

In the 1960s, researchers experimented with the psychedelic drug psylocybin, the active ingredient in magic mushrooms, to see if it could induce spiritual experiences in healthy volunteers. The first of these experiments took place on Good Friday in 1962. Harvard researchers administered psilocybin to ten students in the basement of Marsh Chapel at Boston University. The religious setting and the drug together gave rise to religious experiences in all study participants.

(The experiments came to a halt when the US government prohibited them in the early 1970s.)

Psychedelic drugs, such as psilocybin, LSD (lysergic acid diethylamide), and mescaline, affect the dopamine system, the serotonin system, and the adrenergic system. Their effects on the adrenergic systems, which normally cause an increase in the blood concentration of adrenaline, can cause panic attacks and extreme anxiety. The drugs’ effects on the dopamine system are responsible for thoughtless decision making and irrational actions during a “trip,” such as self-mutilation or suicide. The psychedelic effects of the drugs are largely due to their affinity for the 5-HT2A receptor. This receptor is a serotonin receptor. When a psychedelic drug in the serotonin family binds to it, the drug functions just like serotonin.

In normal amounts, the feel-good chemical serotonin yields a sense of relaxation and relief. In large amounts, however, serotonin and serotonin agonists like LSD, DMT (dimethyltryptamine), and the magic mushroom ingredient psilocybin have psychedelic effects. In large amounts, these chemicals trigger the brain’s main excitatory neurotransmitter glutamate, which makes parts of the brain go into an over-excited state.

The effects of excessive amounts of serotonin can be so powerful that our critical sense is turned off. A famous, mind-boggling case illustrating this is the Dr. Fox study. In the 1970s an actor was trained to deliver a brilliant talk on mathematical game theory while saying basically nothing of substance. The actor, who bore the name Dr. Myron L. Fox, had taken a scholarly article on game theory and stripped it of its content. The talk was rife with hedging, invented words, contradictory assertions, and references to his alleged earlier articles and books. Surprisingly, his delivery so impressed the audience that nobody noticed that he didn’t really say anything. At the end of the talk the audience, which consisted primarily of experts, bombarded Fox with questions, which he answered proficiently without providing any substantial content. After the lecture, the audience was given the opportunity to evaluate the performance. Everyone was very positive, they thought the lecture had been interesting, and some noted that Dr. Fox had presented the material clearly and precisely and offered lots of illustrative examples. And these folks were academic experts on the topic of mathematical game theory! Speaking of being fooled by what you hear!

This effect of delivery on audience evaluation has come to be known as “The Dr. Fox effect.” The Dr. Fox effect can be explained by noting that a large surge in “feel good” chemicals will turn off our critical sense. Funny, charming, and persuasive people signal to our brains that everything is as it should be. Their smooth behavior boosts our serotonin levels, which turn off our critical sense and increase our feeling of satisfaction—so much so that our initial beliefs are never subjected to scrutiny in the ventromedial prefrontal cortex and the anterior insula, regions of the brain involved in reflecting critically on new information.

The effects of psychedelic drugs, such as LSD, DMT, and psilocybin, are extreme. Because these drugs cause the brain to enter an over-excited state, they can have seizure-like effects. They furthermore can give rise to hallucinations, illusory color experiences, a feeling of floating , a feeling of one’s identity disintegrating , a feeling of becoming one with the universe, and illusions of time and distance. Thoughts can become uncontrollable, rambling , and obscure, and edged in acid, old memories may blend with new experiences.

While our serotonin levels tend to be low when we fall in love or are beset by a mindless love obsession, there are also states of love that resemble LSD trips. When your passion is unrequited or when you are away from your new love, your serotonin levels drop. But if you unexpectedly bump into him or her or realize that his or her love is not unrequited after all, your brain may release a surge of serotonin, dopamine, and adrenaline, making your mind a bit like the LSD mind. In this state, you may be more likely to see things that are not there, have experiences that are mixed with old memories, and act in irrational ways.

Dopamine by itself can cause people to form beliefs that are not grounded in evidence. People whose blood levels of dopamine are higher than normal are more likely to attach meaning to sheer coincidences and find meaningful patterns in arbitrary scrambled images.

Peter Brugger, a neurologist from the University Hospital in Zurich, Switzerland, examined twenty people who claimed to believe in paranormal events and twenty who claimed they didn’t. When the participants were asked to tell which faces were real and which were scrambled among a series of briefly flashed images, people who believed in paranormal events were more likely than skeptical participants to pick out a scrambled face as real. The results were the same when the participants were tested using words instead of faces. After the initial trials, the researchers administered L-dopa, which has the same effects as dopamine, to both groups of participants. After taking this drug, skeptics made many more mistakes when looking for real words or faces than before taking the drug.

The results of the study suggest that dopamine can make you see things that aren’t there and form beliefs without solid evidential backing. These results may explain the tendency of people in love to idealize their partners and attach meaning to every little move he or she makes. When in love, your dopamine levels are high when you think of your lover. This makes your brain a less reliable instrument for forming solid beliefs or making wise decisions.

Taking the Drug Away

“You are perfect in every way, just not for me,” “I need to find myself and I just can’t do that with you,” “I need to learn to love myself before I can love you,” “I think you feel more than I do and I don’t want to hurt you.”

We know what these are. Breakup lines, the lines of the visible breakups, the lines that put an end to something that once was. The reason a breakup can be so hard to handle, especially for the person who wanted the relationship to continue, is not that the breakup erases the past. It doesn’t. The past is as real as it ever was. When Rick (Humphrey Bogart) and Ilsa (Ingrid Bergman) leave each other in Casablanca, Rick tells Ilsa to focus on the time they fell in love, adding “We’ll always have Paris.” A breakup leaves the past intact but erases the future. It pokes a knitting needle through your expectations for the future. It doesn’t ruin what was. It ruins what was going to come. It shatters the hopes and dreams you had about the future. The losses that hurt most are those that abruptly deprive you of the future experiences you depended on. Those losses make you a different person with a different future and with too many empty spaces to fill with experiences less wonderful than those you had hoped for. A breakup is also a major rejection of you as a person, a demonic destruction of your self-esteem and your self-worth that leaves you raw, open, exposed. As Dennis Quaid once put it, “when you break up, your whole identity is shattered. It’s like death” (Food for the Soul, p. 147).

Breakups often lead to a psychological state that resembles withdrawal from an addiction. They literally take away the crack you were on. So now you experience withdrawal symptoms, making it painfully clear to you just how addicted you were to wonderboy or wondergirl. When you are addicted, you satisfy at least some of the following conditions:

1. You need more and more of the activity or drug for you to achieve the desired effect (tolerance).
2. You experience withdrawal symptoms when you do not engage in the addictive activity or drug.
3. You engage in the activity or take the drug more frequently and for a longer period of time than initially intended.
4. You have a persistent desire to quit or control the activity or drug.
5. You spend a great deal of time ensuring that the activity or drug access can be continued.
6. You give up or reduce important social, occupational or recreational activities because of the addiction.
7. You continue the activity or drug despite knowledge of its physical or psychological consequences.

The severity of your addiction can be seen as a function of how many of these criteria you satisfy.

Addiction is different from obsession in the clinical sense. The main difference is that in cases of obsession, the “drug” consists of recurrent or persistent thoughts or images. In cases of obsession, the obsessive person seeks to control or avoid the thoughts or images by suppressing them or neutralizing them with other less uncomfortable thoughts or with convenient distractors. But the relief is only temporary. What we commonly call “love obsession” typically has both elements of obsession and addiction to a particular person.

A love-obsessed person is in a state of denial, believing that she is still in a relationship, or that she can convince the other person to return to or continue the liaison. The occasional increase in the brain’s levels of dopamine and norepinephrine infuses the tormented and obsessed individual with sufficient energy and motivation to refuse to relinquish. But the “energy high” doesn’t continue. It occurs in intervals. This is because an obsessed individual has widely fluctuating neurotransmitter levels, which makes her go from action-driven to bedridden.

This is the respect in which love obsession differs from drug addiction: when a cocaine addict no longer has access to the drug, his neurotransmitter levels remain low until he recovers or gives in. In love obsession, the neurotransmitters are on a roller coaster ride that makes the obsessed person hang onto the past with ferocious energ y, even when it is blatantly obvious to everyone else that there is nothing to hang onto.

Love obsession following unrequited or unfulfilled love differs from addictions to, or obsessions with, sex and being in love. In the 1979 article “Androg yny and the Art of Loving,” American psychologist Adria Schwartz describes a case of a young man addicted to the chase of women.

A man in his mid-twenties entered therapy after a series of unsuccessful relationships with women. Virtually his entire psychic life was spent in compulsive attempts to meet and seduce women. Occasional successes were followed by brief unfulfilling liaisons which he inevitably ended in explosive fits of frustrated rage, or boredom. Recurrent dreams occurred where he found himself running after a woman, catching up to her only to find some physical barrier between them. Women were “pieces of meat.” He found himself excited by the prospect of imminent sexual conquest, but he often ejaculated prematurely and was physically and emotionally anesthetized to the experience of intercourse.

Addiction to “the chase” is similar to addiction to being in love with someone (or other). People with an addiction to being in love have trouble staying in relationships. When the initial feelings of love turn into a calmer state, they get withdrawal symptoms and end the liaison. The “drug” they need is the cocktail of chemicals that floods the body during the initial stormy phases of a relationship. In the online Your Tango article “Am I Addicted to Love and Sex?” Sara Davidson, the author of "Loose Change" and "Leap," describes her love addiction as an addiction to being in love with someone who is in love with her. The relationship that made her realize that she was a love addict was with a man she “didn’t even like.” She describes her relationship as follows:

Okay, I know, this sounds like an addiction, but I didn’t recognize it until an affair I had last year with a man I call Billy, The Bad. Billy pursued me and wouldn’t take no for an answer. He wore cowboy boots, wrote decent poetry and drove a hybrid Lexus. “I have a tux and a tractor,” he wrote in his online profile. “I can work with my head or my hands.” He said he loved me and took it back, said it again and denied it again. When he turned on the love it was bliss, and when he withdrew it was hell. When he told me again that he loved me the pain went away, only to return with greater intensity the next time he reneged. I cut things off when I couldn’t stand it anymore. I mean, I realized I was crying over a man I didn’t even like! Something deeper, more primitive was clearly going on, and I turned to books and even a 12-step program for help.

In the Psychology Today online article “Can Love Be an Addiction?” Lori Jean Glass, program director of Five Sisters Ranch, reveals that she once was diagnosed with an addiction to being in love. Unlike Davidson, Glass describes her addiction as more than just being addicted to the feeling of being in love. For her, the addiction involved being completely absorbed in someone else’s life and the feeling that someone else needed her and admired her. Someone, anyone; it didn’t matter who it was as long as it was a warm body capable of overflowing her brain with love chemicals. Glass also describes her insanely intense relationship as jumping : “I went from relationship to relationship. The idea of intimacy was foreign. God forbid, I let anyone see inside my wounded spirit. Often, I had several relationships on the back burner, just in case. Keeping the intrigue alive and active was important.”

Addicted to Grief

The emotional responses to a thorny breakup can resemble the responses to the death of a loved one. You feel weighed down by the memories, the longing, the wistful tears, the chest pain and the aching throughout the whole body. Or you are so outraged that you are lucky not to have a semi-automatic weapon. Or you are ready to go on a secret mission aimed at reversing the terrible outcome. It’s no coincidence that breakups can resemble the death of a loved one. When a loved one dies, you grieve. But death is not the only trigger of grief. Grief can occur after any kind of loss: the loss of a job, a limb, a breast, a home, a relationship.

According to the Kübler-Ross model of grief, also known as “The Five Stages of Grief,” first introduced by Elisabeth Kübler-Ross in her 1969 book,"On Death and Dying," grief involves five stages: denial, anger, bargaining, sadness, and acceptance. After the loss of a loved one, you may first deny that the person is gone, simply refuse to believe it. Once the truth dawns on you, you may feel outraged and attempt to convince the beloved to come back or beg God or the universe’s spirits to reverse their decision. Once you realize things are not going to change, sadness sets in. Over time you may finally accept what happened. These stages need not occur in this order, and each stage may occur several times. The different emotions can also overlap. You may be angry and in a bargaining mode at the same time, or deny what happened and still feel sad. Philosopher Shelley Tremain captured the complexity of grief well when she wrote on her Facebook site, “Today  would have been my father’s eighty-first birthday. Some days, I think time is on my side, that it’s getting easier to live with losing him. Then, it happens. Sometimes, it’s a figure of speech he was fond of, at other times, I am shaving him, or I look in the mirror and see the features of my face that are his, or we are sitting together holding hands. Just sitting there.”

Sometimes it is nearly impossible to let go of grief. When you continue to grieve a loss for a very long time, your condition is called “complicated (or pathological) grief.” The love story of Queen Victoria and Prince Albert is a heartbreakingly beautiful illustration of complicated grief. Alexandrina Victoria was eighteen when she became Queen of England. Her Uncle, King William IV, had no surviving legitimate children. So Victoria became his heir when he died in 1837. When Prince Albert, her first cousin, visited London in 1839, Victoria immediately fell in love with him. Initially Albert had doubts about the relationship, but he eventually fell in love with her too. The couple got married in February 1840. During the next eighteen years Queen Victoria gave birth to nine children. She loved Albert deeply. Albert was not only a dutiful husband and the father of Victoria’s children, he was also Victoria’s political and diplomatic advisor. For twenty-one years they lived happily together. But the bliss came crashing to a halt when Prince Albert died of typhoid at Windsor on December 14, 1861.

Albert’s death completely destroyed Victoria emotionally. She was overwhelmed by grief and refused to show her face in public for the next three years. People began to question her competence, and many attempted to assassinate her. Victoria finally appeared in public but she refused to wear anything but black and mourned her Prince Albert until her own death in 1901. Victoria’s forty-year-long state of mourning earned her the nickname “The Widow of Windsor.” She never again became the happy and cheerful woman she had been when Albert was alive. In preparation for her own death she asked for two items to be in her coffin: one of Albert’s dressing gowns and a lock of his hair.

Complicated grief is so severe that psychiatrists now consider it for inclusion in the psychiatric manual for diagnosing mental disorders. If you have complicated grief, you have been grieving for six months or more. You furthermore satisfy at least five of the following criteria:

1. You have obsessive thoughts about aspects of the lost relationship or the person you were with.
2. You spend a significant amount of time every day or almost every day, thinking about your lost relationship or the person you were with.
3. You have intense emotional pain, sorrow, pangs, or yearnings related to the lost relationship.
4. You avoid reminders of the loss, because you know that reminders will cause you pain or make you feel uncomfortable.
5. You have problems accepting the loss of the relationship.
6. You have frequent dreams that relate to your lost relationship.
7. You frequently suffer from deep sadness, depression, or anxiety because of the loss.
8. You are angry or feel a deep sense of injustice in relation to the lost relationship.
9. You have difficulties trusting others since the relationship ended.
10. The loss of the relationship makes it difficult for you to find pleasure in social and routine activities.
11. Your symptoms make it difficult for you to function optimally on your job, as a parent or in a new relationship.

Complicated grief is emotionally and chemically similar to post-traumatic stress disorder. In fact, some psychiatrists argue that there is no need to include complicated grief as a separate psychological condition. They are variations on the very same disorder, they say. Posttraumatic stress disorder can occur as the result of any traumatic event. The most common traumatic events discussed in the literature on posttraumatic stress are events of war, terrorist attacks, brutal physical and sexual assaults, and traffic accidents. It is not commonly noted that unexpected breakups and other traumatic relationship events can also lead to posttraumatic stress.

Posttraumatic stress disorder is a condition in which you keep reliving the traumatic event— for example, the breakup—avoiding situations that are similar to the one that led to the trauma. You furthermore have difficulties sleeping, you feel angry, you have difficulties focusing, and you suffer from anxiety. To be a clinical case of posttraumatic stress disorder, the symptoms must last more than a month and lead to difficulties functioning socially, on the job, or in other areas of life. Posttraumatic stress disorder is more likely to occur if the adrenaline surge at the time of the event was very intense.

A study published in the May 2008 issue of Neuroimage suggests that complicated grief sometimes occurs because a normal grieving process turns into an addiction. Led by neuroscientist Mary-Frances O’Connor, the team looked at images of the brains of people who satisfied the criteria for complicated grief and people who weren’t grieving and found significantly more activity in the nucleus accumbens of the people with complicated grief. Activity in the nucleus accumbens is associated with addiction.

It may seem strange that you could actually become addicted to emotional pain and a longing for a person who is no longer with you. The researchers suggest that your yearning and sadness may give you some type of pleasure or satisfaction.

Perhaps the turmoil of emotions does really provide some kind of gratification. Perhaps this emotional overflow is addictive. But it is also possible that the increased activity in the nucleus accumbens signifies increased dopamine levels of the sort found in certain anxiety disorders, such as obsessive-compulsive disorder (OCD). The classical case of this disorder is one in which the afflicted is obsessed with thoughts of disease and germs and compulsively washes his or her hands after being near other people or anything that could possibly carry microbes. This disorder is associated with low levels of the mood-enhancing chemical serotonin and fluctuating levels of the motivator chemical dopamine. The low levels of serotonin cause anxiety that involves obsessive, jazzy thinking and the dopamine “reward” motivates the afflicted person to behave in compulsive ways.

As people ruminate obsessively over the events leading up to the loss in complicated grief, the condition may turn out to be similar in this respect to obsessive-compulsive disorder. Low levels of serotonin may trigger obsessive thinking, crippling anxiety, and a visceral yearning for the absent person or the irretrievable relationship. The dopamine response elicited by this kind of obsessive thinking and longing may motivate the grief-stricken person to engage in begging and bargaining and it could also ignite anger fits and a ferocious denial of the loss of the relationship.

Excerpted from “On Romantic Love: Simple Truths about a Complex Emotion” by Berit Brogaard. Copyright © 2015 by Berit Brogaard. Reprinted by arrangement with Oxford University Press, a division of Oxford University. All rights reserved.