Nancy Matos

Reader Question: Can you have SAD (Seasonal Affective Disorder) in summer? I thought it only happens in winter days, when it's cold and dark.

Could you explain “Seasonal Affective Disorder”?

My comments: Seasonal Affective Disorder (SAD) is a mood disorder where a person experiences depression during the winter months. People also refer to it as the “winter blues”. The American psychiatrist Norman Rosenthal was the first to identify the illness in 1984.

With the onset of less sunlight and darker, long days in the winter, many people can develop depressive symptoms and a general feeling of sadness and poor well-being. Some of the symptoms include feelings of hopelessness, lack of appetite or changes in appetite, including cravings for sweet and starchy foods, loss of energy and oversleeping.

Regions that experience less daylight in the winter months, including Northern Canada and Scandinavian countries, tend to have more SAD sufferers. SAD is estimated to affect approximately 5 percent of people in the United States but the condition is far less common in China and Japan, according to Encyclopedia Britannica.

However, a form of SAD does exist in summer known as Spring and Summer SAD (Summer Depression). According to the Mayo Clinic, symptoms of summer-onset seasonal affective disorder include anxiety, insomnia, irritability, weight loss and increased sex drive.

To treat SAD in the winter, the Mayo Clinic advises spending more time outdoors or sitting closer to bright windows while at home or at work. Antidepressants and psychotherapy can help people cope with SAD. But because lack of sunlight is the main cause of SAD, light therapy has been shown to be an effective treatment as it mimics outdoor light. Portable devices known as “light books” or “light boxes” which emit a bright yet mild light can be used while reading a book or having a meal.

Lack of vitamin D has also been shown to be a factor in SAD sufferers. As exposure to sunlight stimulates vitamin D in the body, it can increase a person’s positive mood. But a study published in March 2009 in the Journal of Affective Disorders found this may not be the case. Over 3,260 people in China took part in the study, where researchers examined blood samples taken from Chinese between the ages of 50 and 70 to discover how much vitamin D they had in their blood. The participants filled out a psychological questionnaire which tested their mental well-being. The results showed people with higher vitamin D levels could be just as depressed as people with lower concentrations in their blood.

本文仅代表作者本人观点，与本网立场无关。欢迎大家讨论学术问题，尊重他人，禁止人身攻击和发布一切违反国家现行法律法规的内容。

Related stories

Burst one’s bubble

See eye to eye

Spare tire

Eat humble pie

Have a cow

Dead soldier

Upper crust

Hit the jackpot

Juggle的活用

Nancy Matos is a foreign expert at China Daily Website. Born and raised in Vancouver, Canada, Nancy is a graduate of the Broadcast Journalism and Media program at the British Columbia Institute of Technology. Her journalism career in broadcast and print has taken her around the world from New York to Portugal and now Beijing. Nancy is happy to make the move to China and join the China Daily team.