Let's start 2012 on a positive note.

Last year, a study published in the Proceedings of the National Academy of Sciences indicated older people who report feeling happy and content may experience increased longevity. News coverage of the study reported that "older people were up to 35 percent less likely to die during the five-year study if they reported feeling happy, excited and content on a typical day."

I qualify as an "older person," and I've had my share of ups and downs. But I like to think I can count myself among those who self-report their lives as generally happy, and I believe this has contributed to my ability to bounce back from life's challenges.

The recent study doesn't establish a clear cause and effect between happiness and longevity, but other medical findings and established knowledge about the physiological effects of stress are in line with the results.

Consider, for instance, that cortisol, a hormone released when we experience emotional stressors, increases blood glucose levels, alters immune responses and suppresses digestion. This is all designed to enable our muscles to expend energy in a fight-or-flight situation, but it's not so good for us over extended periods of time. Long-term stress can contribute to heart disease, sleep disorders, digestive problems, mood and memory disorders and obesity.

There are many contributors to happiness and life satisfaction. From a medical standpoint, we know that adequate sleep, a balanced diet and regular exercise are among the lifestyle choices that can help us feel good in general. Psychological studies have found that meditation or prayer, friendships, volunteering and maintaining a sense of humor are behaviors often exhibited by emotionally healthy people.

Seeking professional help if you feel depressed for an ongoing period is also important. Depression is a real disorder, and it can be treated successfully. There's no need to suffer in silence.

I wish you all a healthy, happy and blessed new year in a long, long life!

Hank Clever, MD, is a well-known pediatrician in the St. Charles community. Send questions for Dr. Clever c/o Public Relations Department, SSM St. Joseph Health Center, 300 First Capitol Drive, St. Charles, MO 63301.