Psychologist Timothy D. Wilson says spending a lot of time reflecting on the past  -- a favourite passtime for many at this time of year -- can screw you up worse if you're mildly depressed.

An excerpt from the Dec. 29 NYT op-ed piece:

For years it was believed that emergency workers should undergo a debriefing process to focus on and relive their experiences; the idea was that this would make them feel better and prevent mental health problems down the road. After 9/11, for example, well-meaning counselors flocked to New York to help police officers, firefighters and rescue workers deal with the trauma of what they had seen.

But did it do any good? In an extensive review of the research, a team led by Richard McNally, a clinical psychologist at Harvard, concluded that debriefing procedures have little benefit and might even hurt by interrupting the normal healing process. People often distract themselves from thinking about painful events right after they occur, and this may be better than mentally reliving the events.

What can we do to improve ourselves and feel happier? Numerous social psychological studies have confirmed Aristotle's observation that "We become just by the practice of just actions, self-controlled by exercising self-control, and courageous by performing acts of courage." If we are dissatisfied with some aspect of our lives, one of the best approaches is to act more like the person we want to be, rather than sitting around analyzing ourselves.

Social psychologist Daniel Batson and colleagues at the University of Kansas found that participants who were given an opportunity to do a favor for another person ended up viewing themselves as kind, considerate people - unless, that is, they were asked to reflect on why they had done the favor. People in that group tended in the end to not view themselves as being especially kind.

The trick is to go out of our way to be kind to others without thinking too much about why we're doing it. As a bonus, our kindnesses will make us happier.

A study by University of California, Riverside, social psychologist Sonja Lyubomirsky and colleagues found that college students instructed to do a few acts of kindness one day a week ended up being happier than a control group of students who received no special instructions.

As the new year begins, then, reach out and help others. If that sounds suspiciously like an old Motown song or like simplistic advice from one of those do-gooder college professors, well, it is. But the fact is that being good to others will ultimately make us kinder, happier people - just so long as we don't think too much about it.