Why do some people recover after a heart attack while others don’t?

I am a psychiatrist who has spent the last 13 years focusing on improving the mental health of people who have heart disease and other medical conditions. Over time, as I saw more and more hospitalized patients who had just had a major heart-related medical event, I felt that I had a good sense about who was going to recover successfully and who was not. While factors like weight, diet, smoking, and family history are well-documented in medicine, psychological ones were not. In fact, I found motivation, and hope, and gratitude seemed crucial to recovery.

It wasn’t all about whether a person was depressed. The presence—or lack—of positive emotions played a huge role in how well people did after the hospitalization. I’d meet people who were temporarily depressed—but hopeful about getting better—and they did well. And I met people who were not depressed, but not happy or grateful or hopeful—and they did not.

I carried these thoughts in my mind without knowing what to do with them. Then, one day I was in a bookstore and I came upon Sonja Lyubomirsky’s The How of Happiness. Its description of positive-psychology exercises (about which I knew nothing) and the use of such exercises to actively cultivate gratitude, optimism, and other forms of well-being set off a light bulb. This, I thought, is what people with medical illness need: ways to access the good things in their life, mobilize their strengths and resilience, and see better things moving ahead.

I sent Sonja an email out of the blue, and she was incredibly gracious in helping me to chart a course for using these exercises in our patients with heart disease. Our team has now studied positive psychological well-being and cardiovascular health for the past 10 years, including developing a program to promote well-being in patients with heart disease and other medical conditions.

More recently—with the support of the Greater Good Science Center—we have zeroed in on what research has identified as one of the most powerful aspects of psychological well-being: gratitude.

We’re finding that gratitude—toward family and other loved ones, toward health care providers, for one’s health, for even being alive—can be an incredibly powerful and invigorating experience. Furthermore, there is growing evidence that being grateful may not only bring good feelings. It could lead to better health.

How gratitude works

Now, you would think that feeling grateful after surviving a major heart event would be common. But gratitude is complicated and requires some moderately complicated mental gymnastics.

• First: Hey, this good thing happened.
• Second: Hey, the source of this goodness comes not from me, but from some external source.
• Finally: Boy, I am glad about this external source.

Indeed, not all people experience gratitude in this context. For example, one-half of people report experiencing significant gratitude after a heart attack—and by extension, half do not.

We completed in-depth interviews with heart attack patients, in the hospital and then three months later, and we heard a ton about gratitude. We learned that the nature and focus of health-related gratitude can really vary. Some people are naturally and regularly grateful as part of their disposition, while others may not be regularly prone to appreciation but in certain moments experience it strongly.

We also discovered that the subject of the gratitude can differ. Some feel grateful for their spouse, family, and friends; some feel grateful for the doctors and nurses who may have helped or even saved them; and others may feel grateful not for a person but for broader concepts, such as being grateful for their health, even grateful to be alive.

Having learned about the experience of gratitude in patients with heart disease, we now had an important question: Does this experience of gratitude make a difference in terms of health—and taking care of one’s health—after a major medical event like a heart attack? There had been remarkably little research on this topic despite how common and powerful this experience of gratitude is.

In our Gratitude Research in Acute Coronary Events (GRACE) study, we enrolled 164 people at Massachusetts General Hospital who had recently suffered a heart attack, and had them return in two weeks, at which point we had them complete a formal measure of overall gratitude and questions about specific gratitude related to health. We then six months later had them wear step counters for a week and gathered additional information about their recovery.

We asked people about overall gratitude as part of their disposition, as well about specific, in-the-moment, health-related gratitude to learn whether either or both of these kinds of gratitude were linked with better health outcomes. When we asked about this specific gratitude, we asked people to rate their agreement with statements like, “Over the past week, I have been feeling thankful toward my family and friends”; “Over the past week, I have been feeling thankful about my health”; and “Over the past week, I have been feeling thankful about the doctors, nurses, and other staff who helped to take care of me when I was in the hospital and afterwards.”

We found that people who reported feeling more gratitude after two weeks also reported six months later that they had taken their medication more reliably, maintained a healthier diet, and gotten more exercise than their less grateful counterparts. They also reported better health-related quality of life and lower rates of developing depression and anxiety. These connections were above and beyond the effects of age, gender, how severe the heart attack was, their overall medical health at two weeks, and numerous other factors. This overall dispositional gratitude was not associated with the number of steps people took when measured on a step counter.

We also found that in-the-moment gratitude for one’s heath had even stronger associations with health itself. This specific form of gratitude was an independent predictor of good health six months later.

How we learn to be grateful

Ok, so feeling grateful might help your health in both the short- and long-term, according to our work so far.

But are grateful people just grateful people—you either have it or you don’t? Or is it possible to actually teach, guide, cultivate gratitude in people with a medical illness, to try to improve their well-being and promote better recovery and health? Our team is convinced that it is possible to promote a more positive, healthy, and deeply grateful approach to life—and we have been testing out this proposition for the last several years.

To develop such a program, we adapted exercises that research has found reliably boost well-being. Many of them focused specifically on developing gratitude, such as keeping a gratitude journal and writing a letter of gratitude. We wanted to see if the exercises would have a measurable impact on health and whether they could build the habits that would improve well-being.

We first tested it out in patients with a recent heart attack. We gave them a treatment manual and asked them to complete writing exercises independently. A study trainer called them every week over eight weeks to review the activity they were assigned, the emotions it provoked, and how it might fit in their daily lives. We also allowed people to choose the prior activities that were their best fits for the last two weeks.

In our initial study of this program in 47 patients with heart disease, we found that the program was very well-accepted, with over 80 percent of all possible exercises completed. And people who received the program, compared to those getting usual treatment, experienced much greater improvements in positive affect, anxiety, and depression.

“This program helped me realize how lucky I am,” wrote one participant. “There’s definitely a connection between positive emotions and activity levels.” Another said, “It’s given me more confidence; I am stronger emotionally, and that makes me stronger physically.”

In fact, we consistently found in this study and others that people report the greatest benefit from the gratitude-based exercises, especially the gratitude letter. Since that time, we have studied this program in a larger group of heart-attack patients and found that it was associated with more positive feeling, healthier eating, and more physical activity, as well as less depression and anxiety.

How gratitude can help us stay healthy

How might saying “thanks” influence physical health?

Well, first, gratitude might influence behavior, specifically around what we call self-care—becoming more active, not smoking, eating more healthily, and taking medication. It’s often the case that gratitude helps patients feel like they’re being given a second chance, which can drive them to take advantage of what life has to offer.

That means, for many people, getting and staying healthy, for themselves and also for a spouse, children, or other loved ones. These powerful, grateful feelings can lead to feeling more engaged, energized, motivated, and ready to make change. Certainly, that’s what we saw in the GRACE study.

Gratitude might also have beneficial biological effects that help the cardiovascular system and overall health. Studies of various measures of positive psychological well-being, from happiness to optimism to gratitude, have found that experiencing well-being more frequently and more strongly is associated with lower levels of inflammation throughout the bloodstream and the body, a calmer fight-or-flight autonomic nervous system, and other effects that are clearly linked with better prognosis and longer survival. Beyond momentary happiness or pleasure there is some suggestion that deeper well-being—like having life satisfaction, gratitude, and a sense of life purpose—might have much stronger effects on long-term health.

Our group is not certainly alone in studying the effects of gratitude—two other teams in California who have studied programs focused on gratitude found that gratitude journaling, in patients with and without heart disease, led to improvements in well-being, physical activity, inflammation, and that autonomic fight-or-flight nervous system.

Taken together, all of these findings are beginning to suggest that experiencing gratitude—particularly in-the-moment, specific gratitude—may not only increase your well-being and outlook, it might make you change your behavior and lifestyle, which could in turn help you to live longer and better.

The benefits of gratitude are not just available to the naturally grateful, nor are they reserved just for life’s happiest occasions. Indeed, they are important even—perhaps especially—during some of our scariest and most challenging moments, like when we find ourselves in a hospital bed, confronting our own mortality.