MOSCOW, Jan. 19 (UPI) -- Russian President Dmitry Medvedev's decision to end daylight saving time, creating darker mornings, can negatively affect mood and health, some experts say.
Medvedev's decision a year ago to switch to "permanent summer time" came after studies showed the semiannual switch to daylight saving time caused what state-run RIA Novosti called "an unnecessary strain on public health."
But now some experts say dawns coming an hour later can endanger people's health and have a negative effect on moods and work. They say the human body can deal more easily with an additional hour of darkness in the evening than in the morning.
Viktoria Arshinova, a senior researcher at the laboratory of medical and psychological rehabilitation of the Moscow State University of Psychology and Education, said people's bodies and minds are more likely to rest and sleep when it's dark outside, and with the end of daylight saving time, many felt exhausted.
That results from people being forced to adjust their biological clocks to social ones and can lead to depression, as people feel they're deprived of energy and time, and the "silent aggression" of depression will lead to increased drug and alcohol abuse, Arshinova said.
"Our daytime alertness is now in discord with the clocks of nature. Our internal, biological clocks are not synchronized with the external, social time," she said.