Light therapy at bus stops to cheer north Sweden commuters

In the depths of winter, daylight in Umeaa, around 500 kilometres (300 miles) north of Stockholm, lasts only around four and a half hours, meaning that many people catch a glimpse of the sun only through an office window.

"You feel tired during this time of the year, and getting an extra dose of light feels refreshing," said Anna Norrgaard, head of marketing at Umeaa Energy. Over the next three weeks, the company will help commuters combat winter depression by installing light therapy panels at 30 bus stops.

The bus shelters' illuminated advertising boards were replaced Monday by special light therapy lamps. Five of them will be fitted with special overhead panels to enhance the effect.

"You should stand in front of the lamps ... and keep your eyes open to let the light in," Norrgaard said.

However, people in the northerly town, where winter temperatures sometimes creep down to minus 30 degrees Celsius (minus 22 Fahrenheit), should not expect to get a tan, since the ultraviolet radiation has been filtered out.

They may also want to catch a later bus if they are to enjoy the full benefits of the treatment, since half an hour's exposure per day is the "benchmark" used in professional light therapy, according to Norrgaard.

The time "varies between individuals," she added.

Seasonal Affective Disorder (SAD) is a type of depression often directly related to the lack of light in winter.

According to Britain's National Health Service, one theory links the condition to the effect of light on a part of the brain called the hypothalamus, which controls mood, appetite and sleep.

(c) 2012 AFP