Can Daylight Saving Time Clock Change Cause Depression? New Study Says There’s A Link

Daylight saving time clock changes and depression may sound like two completely different things, even as many people believe that the whole concept of springing forward and falling back is an unnecessary, and maybe even harmful one. Higher crime rates, higher risk of health events, and higher incidences of car accidents are all problems that have been linked with the switch back to standard time. But a new study suggests that people may indeed suffer from depression from such a switch, adding to all the other unpleasant consequences linked to turning back the clock to shift out of DST.

A new multinational study involving researchers from the United States and Denmark revealed last week that daylight saving time clock changes have another potential disadvantage to them, and a serious one at that. Based on their findings, shifting to standard time leads to an uptick in depression cases in the fall.

To come up with their findings, the researchers studied the files of over 185,000 depression cases in Denmark from 1995 to 2012. They then compared depression rates before and after daylight saving time and found that clock changes to standard time had resulted in an 11 percent increase in unipolar depressive episodes. On an odd note, however, there was no decrease in depression rates during the “spring forward” shift from standard time to DST.

In a press release published on EurekAlert, study author Soren Ostergaard from the Aarhus University Hospital in Denmark said that the uptick in depression cases is too significant to be dismissed as a coincidence.

“We are relatively certain that it is the transition from daylight saving time to standard time that causes the increase in the number of depression diagnoses and not, for example, the change in the length of the day or bad weather. In fact, we take these phenomena into account in our analyses.”

Ostergaard also noted that the daylight saving time clock change doesn’t just manifest in a general sense, but also affects the severity of depression cases diagnosed in the aftermath of the shift from DST to standard.

“We expect that the entire spectrum of severity is affected by the transition from daylight saving time to standard time, and since depression is a highly prevalent illness, an increase of eight percent corresponds to many cases.”

In a separate statement made to the Washington Post, Ostergaard described his group’s study as the first of its kind to address the question of whether transitioning from daylight saving time to standard time is connected to depression or not. The study, however, didn’t specify the exact reasons why people may get the blues after “falling back” one hour to switch to standard time.

The authors believe that the lack of improvement in depression rates when clocks move forward in the spring means depression isn’t caused by time shifts in a broad sense, but rather the shift itself from daylight saving time, the clock change that has people moving into standard time in the fall.

“One possible explanation is that the sudden advancement of sunset from 6 p.m. to 5 p.m. . . which in Denmark marks the coming of a long period of very short days, has a negative psychological impact on individuals prone to depression, and pushes them over the threshold to develop manifest depression,” the authors said in the study.

With standard time already in effect as of this writing, it wouldn’t be surprising if you may run into people who aren’t their usual selves on the first day of the time shift. But as Ostergaard warned, his team’s study on daylight saving time and corresponding clock changes to standard time should be taken seriously not only by the general public, but also by healthcare professionals, particularly those who specialize in treating depression.

[Featured Image by Joe Raedle/Getty Images]