By Dr. Ronald Pies, Globe Correspondent  | November 20, 2006

We’ve all heard about the holiday blues, but much of what we think we know about them may be wrong.

First off, the notion that the winter months lead to a big surge in suicide is generally not supported by careful studies. According to the National Center for Injury Prevention and Control, US suicide rates are lowest in winter and highest in late spring. Explanations for this finding abound: Most emphasize the painful disparity between the chirpy happiness many feel with the coming of spring and the consuming misery of the severelydepressed person.

As Dan Romer of the Annenberg Public Policy Center of the University of Pennsylvania recently wrote in an e-mail, “We argue in our work that there is no evidence of an increase in suicides during the holiday period and that suicide rates are actually lower during this period in the US.”

That’s the good news. The not-so-good news is threefold. First, there is some evidence from European studies — not yet replicated in the United States — that attempted suicides may actually increase shortly after some winter holidays. For example, in one Danish study, there were fewer suicide attempts than expected just before Christmas. But just after Christmas, there were approximately 40 percent more attempts than expected. There were also more suicide attempts than expected on New Year’s Day.

Why would a spike in suicide attempts not also lead to more completed suicides? It may be that these postholiday “attempts” are mostly “cries for help,” such as minor overdoses in the presence of family.

The apparently delayed effect on suicide attempts has given rise to the “broken promise” hypothesis — in effect, that many people go into the winter holidays with unrealistically high expectations and wind up disappointed by harsh realities. As one sufferer on the MedicineNet website put it, “It’s not really the holidays that cause the blues for me; it’s the postholidays. The fun is over, the bills are due, and the real winter yuck sets in.”

Second, the Christmas/New Year’s holiday period appears to be associated with an increased risk of heart attacks. In fact, research by Dr. David Philips and colleagues found that both cardiac and noncardiac mortality increased around Christmas and New Year’s Day — perhaps because the holiday season is unusually stressful or because distracted holiday partygoers tend to delay urgently needed medical treatment. Heavy alcohol consumption may also contribute to deaths around New Year’s Day.

There is one more piece to the puzzle. Some people are already prone to a type of “winter depression,” sometimes called seasonal affective disorder, or SAD. Folks with SAD typically notice that their mood plummets in the late fall or early winter. They often put on a great deal of weight and sleep much more than usual in winter. Some of these individuals also notice that when spring arrives, their mood and energy level go a bit above normal. This suggests a kinship between some types of SAD and bipolar, or manic-depressive, disorder.

So what can be done about the holiday blues and its risks? Dan Romer’s view is that “we should be aware that the holidays have the potential to increase the blues in some people, but we should probably not focus on the suicide risk as much as the need to seek help from friends/family and/or professionals if the sadness transitions to serious depression.”

It certainly pays to keep your holiday expectations within reason: Holidays are rarely idylls of familial harmony. Avoiding “burnout” is probably a good way to avoid the blues, so it’s a good idea to delegate as much holiday planning, cooking, and cleaning as possible.

Eating and drinking sensibly and seeking medical attention for unexplained symptoms are good policies at any time, but particularly during the holidays.

The holiday blues usually pass in a few days or weeks. But if yours are becoming more intense or you find yourself unable to cope with everyday life, talk to your family physician, mental health professional, clergy, or close friend. With a little planning and forethought, most of us can look forward to a happy holiday season.

Dr. Ronald Pies is clinical professor of psychiatry at Tufts University School of Medicine and a member of the Massachusetts Psychiatric Society.