Yolanda Spencer is eternally grateful for the weekly visits from fellow members of the Bethel AME Church in Jamaica Plain. Without them, she’s not sure how she would have survived the last eight years, since her husband Vincent, now 62, fell off a ladder and became a quadriplegic.

An accident like Vincent’s “is such a devastating thing to happen to a family,” said Yolanda, adding that both of their relatives live far away. Having church members nearby “has been really really supportive.”

A pair of recent studies show just how detrimental such caregiving can be for the health of a spouse. And also, how close social connections like the ones the Spencers, who are black, have with friends from church can offset some of this risk.

Although marriage is generally good for health, the stress of caring for a spouse with a disabling illness can shorten the life of a caregiving spouse, a Harvard Medical School physician and sociologist Dr. Nicholas Christakis showed in a major study published late last month. How well one spouse fares after the death of the other hinges in large part on race, Christakis found in a separate, large study also published a few weeks ago.

While whites married to whites suffer a “large and enduring widowhood effect” when one spouse dies, blacks married to blacks don’t, probably because they have stronger social ties — to church and to extended family — that offset the trauma of losing a spouse, Christakis said.

Actually, it’s the wife’s race that really counts, according to the study, of 410,272 older couples, published in the American Sociological Review. A black man married to a white woman suffers from being widowed just as much as if he were white because her kin might reject him after her death, Christakis suggested. But if a man, black or white, is married to a black woman, he is buffered from the widowhood effect because her black kin accept him as part of the family and continue to provide social and emotional support.

In other words, Christakis said, one of the many things a black wife does is connect her husband with her kin, putting him in a “supportive context” that continues even after her death.

“When you marry someone, you really do marry their family,” said Gail Wyatt, a professor in the department of psychiatry at the David Geffen School of Medicine at UCLA who was not part of the study. “It’s marriage in the context of other people that is the protective thing.”

Many blacks and immigrant families are used to communal caregiving of the very old and the very young, Wyatt said. As immigrants adapt to American ways, however, they tend to “shift toward the white model.”

In general, research shows that marriage benefits a person’s health, especially if that person happens to be male. Married men, on average, live seven years longer than single guys, and married women, two years longer than their single sisters. Married people have better mental health than never-marrieds, too, though, again, it’s men who benefit more from marriage.

But the emerging view of the link between marriage and health is more subtle than that — that “marriage is good for you, except when it isn’t,” as Janice Kiecolt-Glaser, a professor of psychiatry at Ohio State University, put it, only half in jest. In her own work, Kiecolt-Glaser has shown that wounds heal more slowly than normal in caregivers of spouses with dementia, a sign that the stress of caregiving impacts the immune system.

Researchers have long known that the death of one spouse raises, at least temporarily, the risk of death for the surviving spouse. What Christakis’ team showed in the other new study was that it’s not just being widowed that can ruin the health of the healthier spouse, but the stress of caregiving as well. The causes of excess death in the caretaking spouse include accidents, suicides, heart attacks, infections, lung disease and diabetes, according to the study of 518,240 couples aged 65 and older.

In the first 30 days after a spouse’s hospitalization — a marker for the time of diagnosis — the risk of death for the partner was almost as great as it would be if the spouse had died. After a husband’s hospitalization, a wife faces a 44 percent higher risk of death than if her husband were well, the study found. A husband faces a 35 percent increased risk.

Perhaps even more startling, a woman taking care of a husband with dementia or psychiatric illness was at greater risk of dying than if she were actually widowed. Taking care of a spouse with cancer, on the other hand, was much less deleterious to the healthier spouse, probably Christakis said, because cancer, while potentially lethal, is often not as disabling day-to-day.

Suzanne Mintz has been taking care of her husband for 30-plus years, since he was diagnosed with multiple sclerosis. Over the years, she has suffered four bouts of serious depression, in part because of her husband’s illness, and the couple separated twice. They are now back together — with more support, including home health aides. She said she co-founded the National Family Caregivers Association (nfcacares.org), a non-profit advocacy organization in Kensington, MD., in part to help caregivers get the kind of support she needed.

The moral of the story is clear. Get — and stay — married if you can find someone to love.

Take good care of each other. If one of you gets sick or disabled, don’t try to manage alone.

Get help — and social contact — from as many sources as you can, including churches, community groups and social service agencies.

And if you do become widowed, try to maintain the family and community ties you had when you were married. It could be a matter of life or death.

Grieving used to be seen as a very straightforward process: You cried at the funeral, were sad for a few months, then you had some “closure,” and got on with your life.

Psychologists — both pop and professional — thought that anyone who didn’t cry at the funeral or were still crying a year later was either heartless or overly emotional.

But, mercifully, the emerging view among mental health experts is that grieving for a lost loved one is really a disorderly, highly idiosyncratic process — that there are no set stages to go through and no “normal” or “right” way to do it.

For Lynn Osborn, 48, who lost her husband to Lou Gehrig’s disease four years ago after a slow, awful decline, the grieving process “has been very personal, and it’s still not over yet,” she said. “Fortunately, it never occurred to me that there was a “right” way to grieve.”

Osborn, a vivacious woman with a passion for rowing and ballet who is the mother of two sets of twins, now aged 8 and 11, has become something of an expert on grief. She lost her father suddenly to a car crash 16 years ago (“I had had breakfast with him that morning. I came home to a phone call saying he had been killed.”).

Though she had much more time to prepare herself for her husband’s death, it was no less terrible when it actually came than her father’s had been, she said.

As the disease slowly robbed her husband Charley, also a rower, of his ability to pick up his children, feed himself, talk and, toward the end, even blink and smile, Lynn spoke with a psychiatrist at Mass General. “I told him I felt there was a freight train coming. He said, ‘There IS a freight train coming. And there is nothing you can do to prepare for it.'”

Osborn said that insight proved liberating — and very different from the kind of counseling someone in her position might have received in the past.

In the old days, following (or perhaps twisting) the advice of Dr. Sigmund Freud, there was a virtual commandment for people to “process” their grief intensely, then “let go” and, as soon as possible, “move on,” experts said.

But newer research has shown that there is no right way to grieve.

Some people get depressed when a loved one dies. Some don’t. Some move on reasonably quickly. Others maintain a relationship with the deceased that — new research shows — is healthy, not depressing.

“The idea that grief is necessarily a debilitating experience is not true. We cope much better than our social expectations say we will,” said psychologist George Bonanno of Columbia University Teachers College, who has shown that among a group of “normal, everyday people,” only about half will get depressed at any point during their grieving process.

Maintaining a “continuing bond” with the person who has died is also normal. That doesn’t mean living in the past, but honoring the ways in which the relationship, in a sense, still goes on, said Phyllis R. Silverman, an associate in the department of psychiatry at Massachusetts General Hospital and author of the 2004 book “Widow to Widow.” The relationship with the dead person “is a part of who we are. So, much of our life is still connected to that person.”

It’s also very common — and not crazy — for bereaved people to talk to the person they have lost, said Roxane Cohen Silver of the University of California, Irvine: “There is no sign that is unhealthy.”

It is also normal to feel distressed when you realize you are moving on, said Silver, citing the case of a patient who had lost a child. “One of the worst days of her life was when she realized she had gone 15 minutes without thinking about her baby. She realized she was feeling better, but that also got her upset.”

Although there’s no way to fully prepare emotionally for the expected death of a loved one and no “right” way to grieve afterward, there are a few things that can help, said Dr. John Rolland, a psychiatrist and co-director of the Center for Family Health at the University of Chicago.

In a couple, if the husband has a potentially fatal disease and the couple has had traditional gender roles, it may help to begin to “re-organize” these roles while the husband is relatively healthy. The wife may want to look for a job, said Rolland. If she doesn’t know how to balance the checkbook, he could teach her. “You can’t wait until the person is lowered into the ground.”

It also helps, he said, to do some “re-prioritizing so that life goals are focused on the here and now, rather than 30 years later.”

Researchers used to think that grieving before a loved one’s death necessarily made things easier later. But many people are still “shocked by how intense the grief is because they figured they had already done this,” said behavioral scientist Kathleen R. Gilbert at Indiana University in Bloomington.

Osborn has some suggestions, too.

• One is to “record your loved one’s voice. I didn’t figure that out with Charley. But I will do that for my children.”

• The other is to treasure the time you do — and did — have with the person you love.

“I don’t mean to be a Pollyanna, but I had 20 wonderful years with that man,” she said. “There are people who don’t have one day as happy as I had.

“It took me six months after Charley died to realize that that feeling will never go away. It’s like the Grand Canyon. There’s this big hole, and it hurts like hell, but it’s beautiful.”

This is a love story – but one with the kind of anguished twist that millions of Americans must grapple with.

“Betsy, Betsy, Betsy, I love you,” Frederick “Pete” Peterson, now 84 and living in an assisted-living facility in Peabody, used to say, before Alzheimer’s disease slowly stole his brain.

Betsy and Pete Peterson met decades ago when Pete, then an English teacher at Phillips Academy in Andover, hired Betsy to help him run the school’s summer enrichment program.

He was tall, handsome and charming – a recreational sailor with a warm smile and a firm handshake. She was pretty, bright and vivacious. They worked together for a few years until Betsy left to become the first woman dean at Yale College. Then, after Pete’s first wife died, Betsy and Pete saw each other again – and married 22 years ago.

Now, it’s been ages since Pete called Betsy by name. “I miss that,” said Betsy, 62, who lives alone in the couple’s Boston condominium. “After a while, you realize you haven’t heard it. It’s the sort of non-event that marks the transition” from a marriage of soulmates to a strange limbo in which one spouse is alive but has lost much of his personality, while the other is essentially widowed – but without the closure, the rituals that foster healing, or the freedom to rebuild a life.

For years, psychologists had no name for the anguish of situations like that of Betsy. Now they do, thanks in part to Pauline Boss, a psychologist in the department of family social science at the University of Minnesota.

In her book, “Ambiguous Loss,” published by Harvard University Press, Boss explores the corrosive uncertainty and deep confusion faced by people who have lost, yet not quite lost, someone or something dear to them.

Sometimes, the loss occurs when a spouse has Alzheimer’s disease, or a stroke or other brain injury that leaves them alive but “not there.”

Sometimes, it’s the reverse – a loved one is physically absent but psychologically present, as happens, for instance, when children are abducted or vanish.

In fact, that’s exactly what happened 49 years ago to Betty and Kenneth Klein, now 75 and 83, whose three young sons – ages 4, 6 and 7 – simply disappeared one Saturday morning from a playground near their home in Minneapolis.

At the time, the Kleins also had one other son, age 9, and a baby on the way. After their sons’ disappearance, they went on to have three more children. But even a half-century later, their loss is as vivid – and perplexing – as ever.

When a reporter calls, for instance, Kenneth quickly summons Betty to the phone, hope and fear in his voice: “It’s about the boys.” She picks up the phone – and the story. To this day, she said, every time someone walks by or a strange car pulls into the driveway, “I always think, `Is it one of my boys?’ “

She and Kenneth have dealt with their baffling loss by praying, not blaming each other, and sticking together “very tightly,” she said.

The issue of ambiguous loss first intrigued psychologist Boss when she studied the families of pilots who had been shot down over Vietnam and were declared missing in action.

She said she found that, in contrast to more clear-cut losses, such as the death of a spouse, ambiguous losses can be even “harder to deal with because there is no closure, there’s no death certificate, there’s no public validation that this has ended.”

Carol Wogrin, a nurse, clinical psychologist and executive director of the National Center for Death Education at Mount Ida College in Newton, said that “one of the tasks of grief is really knowing that that loss has occurred. Even with a loss as clear cut as a death, she said, people often acknowledge the loss intellectually long before they really know it emotionally.

With a more ambiguous loss, emotional understanding can be harder because, Wogrin said, “a person doesn’t have all those factors that help reinforce” the reality.

It’s dangerous to get into the game of “competitive grief,” downplaying someone else’s pain because you think it’s not as bad as your own, warned Deborah Rivlin, a consultant at the Good Grief Program at Boston Medical Center, a nonprofit program that teaches grief education to children.

Still, she said, ambiguous losses can be particularly difficult, especially because, at least initially, other people may not recognize them clearly as legitimate losses. Many situations, including gradual changes like physical decline or being pushed aside at work, fall into this category.

For instance, parents who have had a stillbirth or lost a hoped-for baby to miscarriage may suffer grief that is all the more painful because the rest of the world fails to acknowledge it. This grief may even be compounded if, as used to happen routinely in hospitals, the “remains” of that pregnancy are whisked away, leaving no tiny body to cry over or bury.

But other situations may also provoke the same kind of long-term, wrenching ambiguity.

It can happen in families in which one member is an alcoholic or addicted to drugs. It can happen to children of divorce who may grieve for the death of the family, even though both parents are present in their lives. And it can happen to spouses of workaholics, who may be home in body, but whose minds are chronically at work, Boss said.

The toughest issue, she said, is the question of how not to become “frozen” in grief and how – and when – to move on.

The Kleins of Minnesota managed to move forward by realizing they had to be strong for their other children, Betty Klein said.

But does moving on, in cases where one spouse has Alzheimer’s, mean that it’s OK for the healthy spouse to form a new romantic relationship?

That issue comes up often, said Paul Raia, a psychologist at the Massachusetts chapter of the Alzheimer’s Association. “The men in my support group will date while the wife is still alive, though it’s very controversial in the group,” he said. “I have never seen a woman do that.

But other mental health specialists, including Dr. Bessel van der Kolk, professor of psychiatry at Boston University, don’t see such a clear gender breakdown on this issue.

“People need to go on with their lives,” he said, though forming a new relationship “raises enormous moral questions.” If the relationship includes sex, he said, it often generates considerable guilt. But short of that, he said, “it’s amazing how many different arrangements people make: Many people find people who meet their emotional needs.”

Betsy Peterson has tried to do just that, learning, as she puts it, “to be a widow” even though Pete is still alive.

She said she feels “very married” to Pete, still works part time as a lawyer and has “reached out a lot in the last few years,” especially to members of her church and book groups.

Even so, it’s tough. But one thought never fails to boost her spirits: “Knowing Pete has been such a gift. His friendship was such a gift. Our marriage is the best thing that’s happened in my life, so I am still ahead, even at this stage. That sense of the gift is one of the ways I get through it.”