Is Daylight Saving Time to Blame for Seasonal Depression?

iStock
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.

5 Holiday Foods That Are Dangerous to Pets

iStock/svetikd
iStock/svetikd

One of the best parts of the holiday season is the menu of indulgent food and drinks that comes along with it. But while you enjoy that cup of spiked hot cocoa, you’ve got to be careful your dog or cat doesn’t nab a lick. Here are five holiday treats that are dangerous for your pets, according to Vetstreet.

1. COFFEE

Any coffee lover will agree that there’s nothing quite like an after-dinner cup of joe on a cold night. But pups, kitties, and other pets will have to sit this tradition out. Caffeine can prompt seizures and abnormal heart rhythms in pets, and can sometimes be fatal. Other caffeinated drinks, such as soda or tea, should also be kept away from your four-legged family members.

2. BREAD DOUGH

We know the threat that bread dough poses to the appearance of our thighs, but it’s much more dangerous to our furry little friends. Holiday bakers have to be careful of unbaked bread dough as it can expand in animal stomachs if ingested. In some dogs, the stomach can twist and cut off the blood supply, in which case the pup would need emergency surgery.

3. CHOCOLATE

Cat and dog in Santa hats chowing down on plates of food
iStock/TatyanaGl

A little chocolate never hurt anybody, right? Wrong. The sweet treat can cause seizures and even be fatal to our pets. Darker chocolate, such as the baker’s chocolate we love to put in our holiday cookies, is more toxic to our pets than milk or white chocolate. The toxic ingredients include caffeine and theobromine, a chemical found in the cacao plant.

4. MACADAMIA NUTS

Macadamia nuts, which are a common ingredient in holiday cookies and often put out to munch on as an appetizer, can be toxic to dogs. While poisoning might not always be easy to detect in a pet, clinical warning signs include depression, weakness, vomiting, tremors, joint stiffness, and lack of coordination.

5. ALCOHOL

Think back to when you first started drinking and how much less alcohol it took to get you tipsy, because you likely weighed less than you do now. Well, your pet probably weighs a lot less than you did, even back then, meaning it takes much less alcohol to make them dangerously sick. Keep those wine glasses far out of reach of your pets in order to avoid any issues. Well, maybe not any issue: We can’t promise that this will stop you from getting embarrassingly drunk at a holiday party this year.

L’Oréal’s New Wearable Sensor Keeps Track of Your Daily UV Exposure

L'Oréal USA
L'Oréal USA

Anyone who has ever suffered a sunburn knows that too much exposure to UV radiation is bad for your skin. But in the moment, it can be hard to tell when you’ve gotten too much sun—especially during the winter, when you might not think you need sunscreen. (In reality, snow reflects up to 80 percent of the sun’s UV light, so you may end up getting hit with the same rays twice.) A new wearable sensor spotted by Wired aims to make understanding your sun exposure a whole lot easier.

L'Oréal’s new La Roche-Posay My Skin Track UV sensor pairs with a smartphone app to alert users when they’ve had high levels of UV exposure. Developed by L'Oréal’s Tech Incubator in collaboration with Northwestern University engineering professor John Rogers and Swiss designer Yves Béhar, the sensor measures UVA rays (which are associated with skin aging and skin cancer) and uses an algorithm to calculate UVB exposure (which is associated with sunburn and skin cancer).

The UV sensor
L'Oréal USA

At only half an inch tall and 1.3 inches long, the waterproof sensor is designed to be discreetly attached to your clothes, watchband, or sunglasses. The sensor's LED detector measures UV rays as sunlight passes through a small window in the device, then transfers the data to your phone via a near-field communication (the same technology in some hotel key cards). It stores the photons from the UV rays in a capacitor, eliminating the need for a battery.

Based on this data, the My Skin Track app can tell you how close you're getting to the maximum limit of UV exposure doctors recommend per day. It also provides updates about the air quality, pollen count, and humidity wherever you are at any given moment. Based on this information, as well as data about your specific skin type and skin tone, the app's Skin Advice feature will provide customized tips for keeping your skin healthy. It also recommends specific products—La Roche-Posay items can be bought directly through the app, should you desire.

The sensors are exclusively available through Apple stores. You can order one online for $59.95.

[h/t Wired]

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