His discovery was sparked by reading a Sports Illustrated article about St. Louis Cardinals slugger Stan Musial.
"He was one of the most beloved baseball players of all time," says Dr. Murray. "He made it a point in his life to make every fan feel appreciated, to let them know he appreciated them.
"That got me thinking about the people I know with health, happiness and longevity (which is a polite way of saying they're old). They all had the common characteristic of being able to express appreciation and gratitude in their life."
Murray is the author of several books on health, the president and CEO of Dr. Murray Natural Living and an alumni of Bastyr University, where he was a longtime board and faculty member. He grew curious about the relationship between gratitude and health — and he found a trove of evidence connecting the two.
Studies show that gratitude corresponds with living longer and with lower levels of depression and other diseases. "I couldn't believe how much research there was," Dr. Murray says. "It's the most important human trait for our ability to live long, healthfully and with a high degree of happiness."
Gratitude doesn't depend on having everything just right in life, but it requires a consistent practice to train oneself, Dr. Murray says. One study found that writing a letter of appreciation to someone and delivering it by hand was a powerful way for depressed people to improve their mood, in both the short- and long-term. Other research has documented the benefits of journaling about thankfulness.
Neurological studies have found that "training" oneself to look for positives increases the mind's ability to experience satisfaction and joy, says Dr. Murray. He says he's been influenced by Martin Seligman, a proponent of "positive psychology," which encourages patients to focus on sources of gladness rather than pain.
Gratitude might seem like the domain of spirituality or religion, not medicine. But doctors who understand mind, body and spirit as connected should consider the potential of gratitude in helping patients seek health, Dr. Murray says.
"There's a reason that the practice of giving thanks became so common in the world's religions," he says. "When you do it, it opens the door to finding more and more to be thankful for."