The Grieving Brain: The Surprising Science of How We Learn from Love and Loss

by Mary-Frances O'Connor

This group of experts identified a list of symptoms characterizing those who were having the most trouble adapting after the death of a loved one. They agreed, based on empirical evidence and clinical experience, that a grieving disorder could be distinguished from disorders of depression or anxiety (including post-traumatic stress disorder). The primary symptoms of this chronic grieving included (1) preoccupation with yearning for the deceased, and (2) traumatic symptoms caused by the loss. Criteria were developed that clinicians and researchers could use to determine if a person they were studying fit this phenomenon of chronic grieving. Creating these criteria was important, because previously, different researchers had used different definitions of what constituted severe grief, making it difficult to compare research studies.

Once we understood that one in ten bereaved people do not adjust over a long period of time, we focused our clinical attention on those who did not improve with the typical support of their friends and family.

Prolonged grief disorder is now included in the International Classification of Diseases (ICD-11) produced by the World Health Organization. It was accepted as a diagnosis in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR) produced by the American Psychiatric Association in 2022. Characteristic symptoms include intense yearning, or preoccupying thoughts of the deceased, on a daily basis. Among other symptoms, there is intense emotional pain, a feeling of disbelief or an inability to accept the loss, difficulty engaging in activities or making plans, and a feeling that part of oneself has been lost. These symptoms occur for at least six months (or for at least a year, in the DSM-5-TR), interfere with the ability to fulfill one’s job, school, or family responsibilities, and exceed what is expected in the person’s cultural or social context.

Even years later, if you have broken a bone, from an X-ray a doctor can still tell it was broken. Grief is similar, in that anyone’s life is forever changed because of loss, even when they have adjusted well. However, there can be complications with a healing bone fracture, like an infection or a second injury, and I think of prolonged and severe grieving in the same way. Usually there are complications that have interfered with the common adaptation process, and the goal is to identify and solve these complications in order to get a person back on track with typical, resilient adjustment.

The group with complicated grief had significantly less brain volume than the nonbereaved group,4 but the brains of the nonbereaved and the resilient bereaved groups were indistinguishable. So greater grief severity in older adults, and not just experiencing bereavement, was associated with a slightly smaller brain volume.

Again, we know nothing about which came first; it’s the-chicken-or-the-egg problem. Did the stress of adapting to a death affect cognitive functioning, or did the older person’s cognitive functioning affect their ability to process the death and its aftermath? Poorer overall cognitive function may lead to more severe grief because it is harder to adjust to loss with less cognitive capacity. Alternatively, cognitive function may be impaired because a prolonged grief reaction may affect the structure or function of neurons, and consequently, the mental functions our brain enables.

CGT provides a therapist-guided imagined conversation with the deceased. During one of these conversations, when Vivian said out loud how much she had loved him, she was flooded with the feeling that he loved her, too. “I think he loved me too much to die while I was in the hospital room,” she said. “Maybe it was a blessing that I left, so he could let go the way he needed to.”

The Trouble with Diagnosing Complicated Grief A mental disorder shares a fuzzy boundary with normative human difficulties. We recognize a mental disorder when a person hears voices that make them believe terrible things about themselves. We recognize a disorder when a person’s crippling anxiety prevents them from leaving their home. When a person cannot remember their loved one’s names, or when they suffer so much psychic pain they wish they were dead, we can identify these states as mental disorders. Psychologists and researchers are working hard to understand and explain the murky boundary between disordered grieving and the universal human pain of loss, through enumerating specific diagnostic criteria, through assessment of functioning in daily life, through exclusions for how long ago the death happened, and whether the reaction appears conventional through the lens of the person’s culture.

I worry about overdiagnosis, from professionals and from grieving people themselves, who are simply trying to explain their experience in a culture that does not understand the universal grieving process.

The moment of separation from a loved one can feel like your heartstrings are being pulled from your chest until they will snap. These attachment bonds, these tethers, are both invisible and intensely real. They keep us connected to our loved ones; motivate us to return to them, like a pliable elastic band; and create a feeling that something is missing when we are apart.

Aching for a loved one while they are alive but far away is useful for maintaining our bond with them; the ache can become unbearable when we know they will never return. People describe the overwhelming pain of grief, beyond individual emotions, as psychic pain. Why does grief hurt so much? My studies of the brain have considered this question, and I believe that the brain has powerful tools, including hormones, neurochemicals, and genetics, to produce this aching and seemingly unbearable sensation.

people who experience a stroke or head trauma that affects the fusiform gyrus lose the ability to recognize familiar faces. This condition, prosopagnosia, prevents them from recognizing even someone as familiar as their husband or wife.

I have heard bereaved people describe this in their own way, saying that the extraordinary stress of grieving feels particularly awful because they are facing it without the one person they would usually turn to in difficult times.

Our need for the people we love, our attachment needs, are so basic that people are at increased risk of early death if they are socially isolated.

This person that you have fallen in love with, whether it is your partner or your baby, has opened new pathways in your brain. To make it clear, it is not just the hormones that are doing this. If hormones are dumped into the brain when you are in a room by yourself, this bonding will not (cannot) happen. It is only when these life-changing experiences happen to us while interacting with the other person that we fall in love—we deeply encode and remember the way they look, the way they smell, the way they feel, and provoke us to yearn to find them, over and over again.

although there are shared features between depression and grief, they are not the same. For one thing, there is no specific person or thing that people with depression are preoccupied with, or yearn for. Depression is a more global experience, a hopeless and helpless feeling that attaches itself to everything that is happening and has ever happened and ever will happen.

Intrusive thoughts are memories of personal events and people that come to mind suddenly and spontaneously, without our intending to recall them. Remembering the loss reminds us of how much we miss them, which leads to feelings of distress or grief. But are intrusive thoughts more frequent than other kinds of thoughts, or do they just feel that way?

When considered from the brain’s perspective, our brain is accessing our thoughts of our loss over and over again. It does the same for important positive events. It is still unpleasant to be caught off guard and have your thoughts and feelings turn to grief. But your brain is bringing them up in order to try to understand what happened, in the same way that you may share memories and stories with friends to talk them through and gain a deeper understanding. When you think of intrusive thoughts this way, it feels more normal that they happen: your brain is doing this for a reason. They seem more functional, and less like a sign you are not handling your grief well.

As our mind wanders, we continue to get reminders from the brain to call or text our loved ones, but now these reminders conflict with reality. Seeing these intrusive thoughts from the perspective of the brain may make them less worrisome. You have always had intrusive thoughts about your spouse, your kids, or your best friend. The emotional impact of them is different now that they have died, but being reminded of our loved ones is the nature of having a relationship. You get reminders because these people are important to us. That does not change right away because the person has died. Your brain has to catch up. It is still running its regular programming of sending out notifications. You are not losing your mind; you are just in the middle of a learning curve.

By generating the “what ifs” in response to yearning, your brain is imagining events that might have played out very differently than they actually did. The alternate reality your brain vividly dreams up, where he did not die but is here with you, is unfavorably contrasted with the present moment in real life. In acute grief, these “what if” responses to the pangs of grief are common and completely normal.

The frequency and intensity of people’s feelings typically increase after a loss, like turning up the volume dial. It is not uncommon to hear people who are grieving say that it is the worst they have ever felt, or that they did not know they could feel so bad. Such emotional intensity forces us to deal with these new experiences. Regulating one’s emotions becomes a necessary part of daily life. Psychologists, friends, and family often have strong opinions about the best ways to cope. Confronting one’s emotions and understanding them has been considered a good coping strategy. Suppressing one’s feelings, and avoiding thoughts that bring up emotions, on the other hand, has been put in the category of bad coping. The most recent research suggests that the subject is not that straightforward, however. The most reliable predictor of good mental health is having a large toolkit of strategies to deal with one’s emotions and deploying the right strategy at the right time.

The “undoing” of negative emotions with positive emotions works because positive emotions change cognitive and physiological states. Positive emotions broaden people’s attention, encourage creative thinking, and expand people’s coping toolkit.

There are at least two reasons why we usually don’t choose mood-boosting activities when grieving. First, doing fun things is not considered the “right” way to act, so we worry what other people will think about our choice. Second, we anticipate that doing something enjoyable after a sad experience will make us feel guilty. When we violate social norms or expectations, guilt is a common response. However, even though people anticipated that they would feel guilty doing something fun, no one in the study felt guilty after watching the funny clip.

If you are listening to your grieving friend and supporting them with the goal of taking away their grief, you will only be frustrated if they continue to grieve despite your loving care. Of course, there is a difference in having compassion for an event that is brief and over relatively quickly like scraping a knee, and for grieving that takes many weeks, months, and even years. It is still vital to provide support, love, and care, but not because it will take away their pain. It is vital because by witnessing, sharing, and listening to their pain, they feel love and we feel loving. In any given moment, though, we may still have to decide if it is wiser to hold them while they cry or to encourage them to get up and keep playing, because flexible approaches to strong feelings are the most useful.

Yearning, anger, disbelief, and depressive moods decrease across time after the death of a loved one.7 These feelings do not follow stages, and people still experience them years after their loss. But their frequency declines as the frequency of acceptance increases. Acceptance may be the outcome of learning that a new reality is here to stay and that we can cope with it.

Psychologists call our thoughts about what could have happened counterfactual thinking. Counterfactual thinking often involves our real or imagined role in contributing to the death or the suffering of our loved one. It is the million “what ifs” that roll through our mind: If I had done this, he never would have died. If I had not done that, he never would have died. If the doctor had done this, if the train had not been late, if he had not had that last drink . . . The number of possible counterfactuals is infinite. Their infinite nature gives us endless thoughts to focus on, to consider and reconsider, turning the scene around and around in our mind.

mulling over these counterfactuals can become a habit, a knee-jerk way of responding to pangs of grief. Although we are trading painful guilt for equally painful grief, at least guilt means we had some control over the situation. Believing we had control, even though we failed to use it, means the world is not completely unpredictable. It feels better to have bad outcomes in a predictable world in which we failed, than to have bad outcomes for no discernible reason.

Well, the truth is, psychologists do not yet have all the answers to when (or how much) processing of thoughts about grief is helpful and when it is not. Researchers are actively grappling with the paradox that you cannot learn about what has happened, and therefore why you feel terrible grief, without focusing on yourself, on your sad and angry feelings. You cannot fully understand what has happened without letting your mind wander through the territory of rumination. At the same time, these ruminative thoughts can develop a life of their own, and when grieving people persist in these repetitive thoughts, they tend to develop complicated grief or depression. Although we do not have all the answers yet, some paths through the paradox are becoming clearer.

Notably, women tend to ruminate more than men, and women also have higher levels of depression. Women scored higher on both reflecting and on brooding than men, suggesting they are more contemplative overall.

My thoughts would spin on why I felt down. I wondered if I was prone to depression because she had been. Or whether I would have turned out differently if she had not been depressed while I was a child. She leaned on me to help her manage her mood, and I was always afraid I would not be able to help her feel better. I learned that I was most successful at helping her feel better, at least momentarily, when I would say whatever she needed to hear or do what she wanted me to. This often meant I had to ignore what I thought or needed. The pattern of believing I should help her feel better at any cost became a well-worn groove. After her death, I repeated this pattern: I struggled to help other people in my life feel better, while I continued to ignore my own feelings. There were endless possibilities for why I felt down, and I carefully examined each one, prolonging the state I was in. It probably didn’t help that I was in a clinical psychology graduate program, where I was training to examine people’s moods and the causes for their feelings. Fortunately, I also learned many problem-solving methods and skills for improving mood, so I did not succumb to rumination all the time.

Grief-related ruminations tend to center on a few topics, as evidenced by Stroebe and Schut, and their colleagues, Dutch psychologists Paul Boelen and Maarten Eisma.2 The five topics include: (1) one’s negative emotional reactions to the loss (reactions), (2) the unfairness of the death (injustice), (3) the meaning and consequences of the loss (meaning), (4) the reactions of others to one’s grief (relationships), and (5) counterfactual thoughts about the events leading up to the death (what-ifs).

All of these topics of rumination are actually questions that cannot be answered, which is why they can persist indefinitely. There is no answer to whether the death was unfair, because there are many facets of unfairness. There is no answer to all the ways that their death has robbed your life of its meaning or joy, because losing a loved one brings an infinite number of changes. The sneaky problem with rumination is that while one is ruminating, it feels as though you are seeking out the truth of the matter. The point is that the thoughts are prolonging our sad or irritable mood, not whether the thoughts are true.

letting our thoughts run through our mind again and again may be a way to distract ourselves from the painful feelings of grief. Thinking about the loss and the consequences of the loss might actually be a way to avoid feeling the loss. She and her colleagues called this the rumination as avoidance hypothesis.4 This may sound pretty far-fetched initially, but luckily this careful research team did empirical studies to investigate. Let me tell you how. When something is very difficult to measure, scientists develop special techniques to measure it—that was the basis for the microscope and the telescope. Avoidance is a difficult thing to measure. Although we can ask people how much time they spend ruminating, or what they ruminate about, it does not make sense to ask people outright about avoidance. If the brain’s motivation for avoidance is not to notice what one is feeling, then avoidance itself as a process probably would not be noticed either. Special measurement techniques in the laboratory, however, allow psychologists to study automatic responses, responses too quick to be deliberate. These decisions are made by the brain very quickly. One method uses reaction time and the other uses eye tracking—responses that happen approximately as quickly as one heartbeat. In order to test the rumination as avoidance hypothesis, Stroebe and her colleagues invited bereaved people to come to the laboratory and participate in these avoidance measurements. They thought using the pictu...

So, rumination is an avoidance process, although not intentional. Repeatedly returning to aspects of the loss or one’s grief that cannot be changed does not help us learn to tolerate the painful reality over the long term. I have known people who have told me that when they stopped trying to avoid feeling grief, grief was not as hard to tolerate as the effort required to avoid it.

She developed the term co-rumination to describe the repetitive, extensive discussion of personal problems between two close friends, an intimate and intense form of disclosure, often about negative feelings. The clear upside I experienced with my best friend was borne out in Rose’s research. Friends experienced these conversations as increasing their feelings of closeness and satisfaction with their friendship.7 On the other hand, co-rumination also led to increased symptoms of depression and anxiety. Support that involves talking about problems extensively may have a negative effect on emotional adjustment rather than a positive one. Ironically, this is a vicious cycle. When one feels more depressed, one may turn to these conversations more and more in order to feel close and supported.

It dawned on me that maybe there was an opposite of both rumination and grief work, and that might be accepting. I use accepting for one’s response to what happens in the moment, rather than acceptance, which suggests a permanent change in how a situation is viewed.

Avoidance—trying to circumvent the knowledge that the death has happened—is effortful. Avoiding the overwhelming feelings of grief, motivated by how much you hate those feelings, requires effort. Accepting, on the other hand, does not have any bearing on whether or not you hate the fact that your loved one died. It simply acknowledges the reality, and stops the reaction there. No ruminating, no problem solving, no anger, no protest—just accepting the way it is.

Beyond the feelings of sadness and anger and amputation that I have already mentioned, pangs of grief can also be full of panic.

In A Grief Observed, the beautiful book C. S. Lewis wrote after the death of his wife, he writes: “No one ever told me that grief felt so like fear.” In the worst moments of grief for me, I would have called it panic. After the death of my father, I had no children, I was no longer married, and I had no parents. For the following year I felt completely untethered in the world, without all the usual attachments that had held me in place.

If grieving didn’t make the present unbearable enough, the insomnia that often comes with grief certainly doesn’t help. The period following the death of a loved one is a perfect storm that dysregulates all the systems that control our sleep. First, our system is pumping out a combination of adrenaline and cortisol in response to the stress of bereavement, enough to keep anyone awake as though they were drinking extra coffee throughout the day. Combine that with all the changes in what insomnia researchers call the zeitgebers, which means “time givers.” Zeitgebers are all the environmental cues that synchronize a person’s biological rhythms to Earth’s twenty-four-hour cycle of light and dark.

You are not alone. As soon as we focus on how grief is manifested in ourselves, as soon as we become fixated on our own experience, we are disconnected from those around us. On the other hand, when we focus on the idea simply that there is grieving, and we are part of it, we find connections. At times we feel ashamed for our strong feelings of grief, or we feel angry at other’s reactions to our mood, or we feel weak or disoriented or worried, and on and on. But if we can stop judging ourselves, if we can have compassion for ourselves because we are human and because this human life comes with grief, we may find it easier to connect with others as well.

C. S. Lewis writes, “I not only live each endless day in grief, but live each day thinking about living each day in grief.” Early on, many grieving people are unable to do much productively, as our mind, our brain, and our body are too dysregulated to function properly without our loved one. But over time, we have an opportunity to learn how to respond to each moment as it presents itself. We can consider what is in our best interest, the pros and cons of spending the present yearning for the past. We may be avoiding what is happening in the present moment, not engaging in what can be seen, felt, and tasted right now. Or we may simply be unaware of where our mind is, in the habit of mind wandering unless our attention is grabbed by something, or unless we are doing a task that requires focus.

Love After a loved one dies, they are clearly no longer with us in the physical world, which each day proves to us. On the other hand, they are not gone, because they are with us in our brain and in our mind. The physical makeup of our brain—the structure of our neurons—has been changed by them. In this sense, you could say that a piece of them physically lives on. That piece is the neural connections protected within our skull, and these neural connections survive in physical form even after a loved one’s death. So, they are not entirely “out there,” and they are not entirely “in here,” either. You are not one, not two. That is because the love between two people, that unmistakable but usually indescribable property, occurs between two people. Once we have known love, we can bring it into our awareness, we can feel it emerge and emanate from us. This experience reaches beyond the love for the flesh and bones of the person we once knew on this earthly plane. Now loving is an attribute of us, regardless of who we share it with, regardless of what is given to us in return. This is a transcendent experience, a felt sense of being loving without needing anything in return. In the very best moments together, we learned to love and to be loved. Because of our bonded experience, that loved one and that loving are a part of us now, to call up and act on as we see fit in the present and the future.

Grieving is the change from having your attachment needs fulfilled by your deceased loved one, to having them consistently fulfilled in other ways. That does not necessarily mean fulfilled by one other person. Having a meaningful life is not the same as remarrying or having another child. In fact, these relationships might distract you from pursuing a meaningful life, if they get in the way of reaching your goal.

If the very nature of our self implies that we have a husband, then imagining ourselves in the future automatically brings him, too. And it’s easy to see why we would feel as though part of our self is missing after our husband’s death, if our identity integrates “wife” as part of “self.” On the other hand, if we have many aspects of our identity that are unrelated to the deceased, such as “sister” or “supervisor,” then events that come to mind are just as likely not to include them.

My relationship with her, present and past, was transformed when I focused on all the good she wanted for me, despite all the difficulties we’d had throughout our relationship.

Gaining a new relationship is simply not going to fill the hole that exists. Here is the key—the point of new roles and new relationships is not to fill the hole. Expecting that they will can only lead to disappointment. The point is that if we are living in the present, we need to have someone who loves us and cares for us, and we need someone to love and care for as well. The only way to enjoy a fulfilling relationship in the future, however, is to start one in the present.