Is Daylight Saving Time to Blame for Seasonal Depression?

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iStock

The precise root cause of seasonal depression has eluded scientists for years. Now researchers think they’ve found the answer: daylight saving time. They published their report in the journal Epidemiology.

Seasonal depression or seasonal affective disorder (SAD) affects around 1.6 billion people across the globe. Its symptoms mirror those of generalized depression; what differentiates SAD is the timing of its onset, which coincides with winter’s shorter days and long, dark nights.

We know that sunlight, or the absence of it, has a powerful effect on our bodies. But scientists have yet to find a definitive physiological link between darkness and SAD, a fact that makes some wonder if there aren’t other variables at play.

Previous studies have found a relationship between the shift from daylight saving into standard time and other health problems, but they had not looked specifically at the transition’s effect on depression. To get a better idea, an international team of researchers looked at Danish hospital intake records from 1995 to 2012, including 185,419 diagnoses of depression.

As expected, they saw an increase in hospital admissions for depression as winter descended. But that increase spiked at one particular time: the month immediately following the changing of clocks.

The researchers controlled for variables like day length and weather, which they say confirms that the 8 percent rise in depression diagnoses was not a coincidence.

And while their study focused on people with severe depression, the authors say the time shift likely affects “the entire spectrum of severity."

Though the study did not identify the mechanism responsible for time change–related depression, the researchers believe it may have something to do with the way daylight saving manipulates our hours of light and dark. Danish daylight saving protocol steals an hour of daylight from the afternoon and moves it to the early morning—a time, the authors say, when most people are indoors anyway.

"We probably benefit less from the daylight in the morning between seven and eight, because many of us are either in the shower, eating breakfast or sitting in a car or bus on the way to work or school. When we get home and have spare time in the afternoon, it is already dark," co-author Søren D. Østergaard of Aarhus University Hospital said in a statement.

Then there are the psychological effects. In changing the clocks, we are forced to acknowledge the arrival of months of darkness, a realization that Østergaard says “is likely to be associated with a negative psychological effect.”

Fortunately, while we still don’t fully understand the causes of SAD, we have found effective treatments. If you find yourself depressed as the year winds down, talk to your doctor and look into a therapeutic light box.

This Cooling Weighted Blanket Helps You Sleep Soundly Without Overheating

Research has shown that weighted blankets, originally made for kids with anxiety and sensory processing issues, may also alleviate stress and anxiety in adults as well. But if you're someone who gets hot easily, sleeping beneath a heavy blanket at night may feel uncomfortable. The Hush Iced, a cooling version of the popular Hush blanket, is designed to change that.

One of the most common complaints Hush Blankets received from customers after releasing its original weighted blanket was that it made users too hot. So the team at Hush tweaked the outer material to make it friendlier to people who are prone to overheating while still providing the soothing deep-touch pressure of a weighted blanket.

The new Hush Iced, currently raising money on Kickstarter, comes with a special ultra-cooling cover. The thin bamboo and cotton fabric wicks away sweat and helps maintain your body temperature through the night. Inside is Hush's classic weighted blanket, with weight distribution technology that helps you feel relaxed and secure in bed. If you already have a Hush weighted blanket at home, the cooling cover is also available separately.

The Hush Iced weigh 15 to 25 pounds, and comes in standard (48-by-78-inch) and queen (60-by-80-inch) sizes. (Generally, Hush recommends choosing the weight of your blanket based on body weight—check out the Hush site for more information on selecting the right one.)

Buy it on Kickstarter starting at $128. The cooling cover is available on its own for $39.

Chronic Pain Happens Differently in Men and Women

iStock.com/PeopleImages
iStock.com/PeopleImages

Women often feel colder than men due to physical differences. Now, a new study shows that the two sexes have different biological processes underlying a specific kind of pain, too. As WIRED reports, research published in the journal Brain revealed that different cells and proteins were activated in men and women with neuropathic pain—a condition that is often chronic, with symptoms including a burning or shooting sensation. While scientists say further research is needed, these findings could potentially change the way we treat conditions involving chronic pain.

A team of Texas-based neurologists and neuroscientists looked for RNA expressions in the sensory neurons of spinal tumors that had been removed from eight women and 18 men. Some of the patients had pain as a result of nerve compression, while others had not experienced any chronic pain. While studying the neurons of women with pain, researchers noticed that protein-like molecules called neuropeptides, which modulate neurons, were highly activated. For the men, immune system cells called macrophages were most active.

"This represents the first direct human evidence that pain seems to be as sex-dependent in its underlying biology in humans as we have been suggesting for a while now, based on experiments in mice," Jeffrey Mogil, a professor of pain studies at Montreal's McGill University, who was not involved in the Brain study, tells WIRED.

So what exactly do these new findings mean for sufferers of chronic pain? Considering that clinical trials and drug manufacturers have traditionally failed to distinguish between the sexes when it comes to developing pain medication, the study could potentially form a foundation for sex-specific pain therapies that could prove more effective. This might be especially promising for women, who are more likely to have some condition that cause persistent pain, such as migraines or fibromyalgia.

"I think that 10 years from now, when I look back at how papers I've published have had an impact, this one will stick out," Dr. Ted Price, a neuroscience professor and one of the paper's authors, said in a statement. "I hope by then that we are designing clinical trials better considering sex as a biological variable, and that we understand how chronic pain is driven differently in men and women."

[h/t WIRED]

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