LIGHT THERAPY: In Britain, the Science Museum’s Dana Centre creates a "light lounge", containing specially designed lightboxes to help SAD patients beat winter blues. [Photo provided to Shanghai Star]

Feel a little glum in colder weather? You are not alone. Wu Ni looks at some simple ways to stay bright and happy when the weather is gloomy.

With fewer hours of sunlight and lower temperatures, it can be a struggle to stay active during winter.

The colder weather makes it more likely that people will feel moody, sleep more but still feel tired or lose interest in their usual activities. And the gloom won’t lift until spring.

The winter blues, if paired with intense symptoms and if it lasts for more than two consecutive winters, can indicate a health complaint called Seasonal Affective Disorder (SAD). This is a type of depression thought to be related to the amount of natural light available in the winter months, according to Zhang Chun, director of the Psychological Crisis Prevention Center in Nanjing, Jiangsu province.

"The lack of daylight makes the body produce a hormone that restrains happiness," Zhang says.

The pineal gland that regulates body rhythms, secretes a hormone called melatonin during the night. Melatonin regulates people’s biological clock and sleep patterns, making people feel drowsy, with low body temperature and heartbeat and prepares the brain for rest.

In the winter months, the lack of daylight can mean some peoples’ bodies do not stop producing melatonin, leaving them feeling exhausted. More symptoms include eating more and craving carbohydrates, weight gain or having trouble concentrating. Women, the elderly and those who work indoors, are more likely to suffer SAD, Zhang says.

Light therapy, using special high intensity "light boxes", is one of the main forms of treatment for SAD sufferers. To get the benefits, sufferers have to sit in front of a light box, which contains a light five to 20 times more intense than a well-lit office, for a certain amount of time each day. However, if one is suffering serious symptoms, one should seek help from doctors for antidepressant medication.