Chris Fagundes, a psychologist at Rice University, said that in his own lab, he and his team have found links between grief, depression and changes to the immune and cardiovascular systems. In one study published in 2019, he and his team performed psychological assessments on 99 bereaved people about three months after the deaths of their spouses, and then took blood samples. Those who experienced higher levels of grief and depression also had higher levels of the immune system’s markers for inflammation.
“Chronic inflammation can be dangerous,” Dr. Fagundes said. “It can contribute to cardiovascular disease, Type 2 diabetes, some cancers.” In another study of 65 people, published in 2018, Dr. Fagundes and his colleagues found that bereaved spouses who had higher levels of markers for inflammation also had what experts refer to as lower heart rate variability — a characteristic that can contribute to an elevated risk for cardiovascular disease.
Other studies have found effects on the cardiovascular system, too. In one, published in 2012, researchers measured the heart rates of 78 bereaved people twice — once for 24 hours within the first two weeks of a spouse or child’s death, and again for the same amount of time six months later. They found that their heart rates were initially faster, then returned to normal, suggesting that the bereaved may have been at least temporarily at higher risk for heart disease. Another study published in 2012 found that those with higher scores on grief assessment tests also had increased levels of cardiovascular clotting factors, possibly raising the risk of developing blood clots.
And in one review of 20 studies, published in 2020, people who scored higher on psychological measures of grief also had higher levels of certain stress hormones like cortisol and epinephrine. Over time, chronic stress can increase the risk of cardiovascular conditions as well as diabetes, cancer, autoimmune conditions and depression and anxiety.
Put the studies together and on the whole, Dr. Fagundes said, “everything starts with the brain.” It responds to the death (and to intense stress in general), by releasing certain hormones that fan out into the body, affecting the cardiovascular system and the cells of the immune system. Aside from that generality, however, the biology of grief has no clear chain of cause-and-effect that the biology of, say, diabetes, has. That’s because the goals of these studies are to better understand the griever’s risks for disease, not to understand the path of grief through the body.
The one exception is with the study of the brain. In 2001, Dr. O’Connor first began imaging the grieving brain, and a handful of similar studies have been done since. In these studies, a person lies immobile in a functional magnetic resonance imaging (or fMRI) scanner, looks at certain pictures and listens to certain words, and the machine maps the blood flow to parts of the brain. In one study published in 2003, Dr. O’Connor found three areas of the brain that were triggered by words related to grief (like “funeral” or “loss”) and a fourth triggered by pictures of the person who died. Some of the brain areas were involved in the experience of pain, others in having autobiographical memories. These findings were “not world-stopping,” Dr. O’Connor said, “like, sure, that’s what happens in grief.”
But the responses recorded in another area, called the nucleus accumbens, were more surprising. This region is part of the brain’s network for reward, the part that responds to, say, chocolate, and it was active only in people with complicated grief. Nobody knows why this is so, but Dr. O’Connor theorized that in the continuing yearning of complicated grief, being reminded of a loved one with pictures and words might have the same reward as seeing a living loved one. In regular, uncomplicated grieving, the reminder is no longer connected to a living reward but is understood as a memory of someone no longer here.