Recent research into how emotions change with age may be able to help people lead healthier and longer lives and bring about new treatments for depression in the elderly.

Like people's bodies, emotions change over time. Older people for the most part have far fewer negative feelings, such as worry and stress, than do younger people, studies show.

The elderly learn to disentangle themselves from feelings of negativity and seem to focus more on present situations that bring pleasure, rather than on the future, researchers say. They also tend to process negative information less deeply than positive information.

By contrast, positive feelings such as enjoyment and happiness change very little from the time a person is in his youth until old age.

'It seems to be essential for our emotionalwell-being to not look back in anger and to focus on the positive when we are older,' Stefanie Brassen, a researcher at the University Medical Center Hamburg-Eppendorf, said in an email.

Older people who are depressed seem not to use the sort of emotionalregulation typically seen in the elderly, researchers say. Depression affects some six million Americans over the age of 65, or about 15% of the total, and is believed to be a big reason why the elderly have the highest suicide rate, according to the nonprofit Geriatric Mental Health Foundation.

In a potential new treatment approach, Dr. Brassen and colleagues are developing a training program in which older people practice strategies to better adapt to life circumstances. The goal is to get patients to 'focus on what they have reached in life, on the resources and abilities they still have and on positive experiences they can plan in the near future,' says Dr. Brassen.

Still, focusing on the positive or what feels good also can create problems, such as impairing decision-making and making older people more vulnerable to scam artists. There are times when one wants to focus on the negative and think through what someone is telling you rather than reacting to how a person makes you feel, says Laura Carstensen, a psychology professor at Stanford University and director of its Center on Longevity in California.

In one study, some 340,000 people ranging in age from 18 to 85 were surveyed by phone and asked how much they had felt emotions like happiness, stress and anger the day before. Between about the ages of 20 and 60, people experienced an increasingly greater ratio of positive to negative emotions, says Arthur Stone, a professor of psychiatry and behavioral science at Stony Brook University in New York, who led a study.

While reported feelings of happiness were generally similar across the decades, 'we saw a drop off in the amount of stress and worry as they get older,' Dr. Stone says. The work was published in the Proceedings of the National Academy of Sciences in 2010.

How people approach life emotionally is driven by changes in their life goals, says Stanford's Dr. Carstensen. Younger people often need to explore or take risks to achieve longer-range goals, and they experience stress and frustration in the meantime. Older people, by contrast, perceive their time horizons as shorter and focus on more immediate goals that elicit positive emotions, like being with their grandchildren, she says.

'As we focus on those [shorter-term] goals, people's lives get better,' she says. In a study published last year, Dr. Carstensen and colleagues found that people who developed a higher ratio of positive to negative feelings as they aged were more likely to live longer. The study, published in Psychology and Aging, followed nearly 200 adults over 10 years.

Healthy elderly people appear to employ coping strategies that help lessen the experience of negative emotion, says Dr. Brassen the German researcher.

She and colleagues ran an experiment to see how young and old people respond to feelings of regret. Interestingly, a third group -- elderly people diagnosed with depression -- responded to regret in ways that more closely resembled the younger group, rather than their similarly aged peers. The study was published in May in the journal Science.

In the experiment, Dr. Brassen engaged 21 healthy young people, 20 healthy older people and 20 depressedelderly in a game of chance. Players had to choose whether to keep on going in the game for the opportunity to win more points. But if they lost in a subsequent round, they would lose all their points.