Winter blues and long winter naps
Do you feel depressed during winter? You're not alone. As the days get shorter, the American Psychiatric Association estimates: about 5 percent of Americans experience a type of depression known as Seasonal Affective Disorder (SAD).
People experiencing SAD tend to have feelings such as: despair, a decreased desire to participate in activities that are generally enjoyed, lethargy. Even people who do not meet the clinical threshold for this disorder may experience increased anxiety and depressive symptoms.
Scientists have linked an increase in SAD and more common winter depression to decreased sun exposure, which leads to lower levels of neurotransmitters. serotonin. Consistent with the idea that sunlight plays an important role, SAD tends to be more common in more northern regions of the world, such as Scandinavia and Alaska, where days are short and winters are long.
We may be special, but humans are not unique in exhibiting these season-related changes.For example, our primate relatives rhesus monkey Indicates a seasonal decline in mood.
Some scientists point out that SAD indicates a number of things. something similar to hibernation — A long snooze that brown bears, ground squirrels, and many other species use to slow down their metabolism and make the most of winter. The disorder is thought to have its roots in adaptations that conserve energy during times when food is usually scarce and colder temperatures place greater energy demands on the body.
Winter is also well known as the season when many people gain a few extra pounds.
According to research, diet in the worst condition, weight highest during winter; recent reviews Many studies have found that the average weight gain during the holiday season is about 1 to 3 pounds. A review showed that people who are overweight or obese tend to gain weight.
There's probably more going on to your year-end weight gain than just eating too many holiday treats.
In the past of our ancestors, in many places, winter meant food became more scarce. It may have been an evolutionary adaptation to this deprivation that people eat more and more in winter, when physical activity decreases.
If ancestors who responded in this way to colder winter conditions had an advantage, evolution would ensure that the adaptation was encoded in their genes and passed on to their descendants.
sex, generosity, concentration
Beyond these winter-related changes in mood and waistlines, this season also brings about many changes in the way people think and interact with others.
One seasonal effect that is less discussed is that people seem to be more active during the winter.Researchers have investigated condom sales, rates of sexually transmitted diseases, and internet search Regarding pornography and prostitution, both have a biannual cycle, peaking at the end of summer. during the winter.
Birth rate data shows that babies are more likely to be born in the United States and other countries in the northern hemisphere during the winter than at other times of the year.
Although this phenomenon is widely observed, the reason for its existence is unknown. Researchers found health benefits for infants born in late summer, when historically food may have been more plentiful, changes in libido due to changes in sex hormones, and increased intimacy motivated by the holiday season. Many explanations have been suggested, including a desire for a relationship or simply an increased opportunity to engage in sexual activity.
But winter stimulates more than just sex. Research shows that people may be more alert at school or work during this time.
Belgian neuroscientists have discovered that measuring task performance maintains sustained performance. Note The best time was near the winter and summer solstices.
And there may be a kernel of truth to the idea of a generous Christmas spirit.
Countries where holidays are widely celebrated tend to have higher rates of charity work. significant increase Around this time every year. And people are becoming more generous with their spending, leaving about 4% more money for servers during the holiday season. This trend is likely a response to the altruistic values associated with winter holidays, which encourage generous behavior.
Like many other animals, we are seasonal creatures.
In winter, people tend to eat more, move less, and mate more. You may feel a little depressed, but at the same time you may find yourself being kinder and more attentive to others. As psychologists and other scientists study these kinds of seasonal effects, they may find that what we know so far is just the tip of the iceberg.
Michael Varnum is an associate professor of psychology at Arizona State University. Ian Holm is a graduate student in psychology at the University of British Columbia.This article was created with the help of conversationa nonprofit news organization.
