December 21 marks the beginning of winter, and also holds the title as the shortest day of the year. With shorter days, longer periods of darkness and the onset of the coldest season ahead, many people find themselves feeling a little “SAD.”

Seasonal Affective Disorder, or more casually known as SAD, can cause low mood and symptoms of depression, and often affects people during the colder seasons when there is less daylight. This is because sunlight affects serotonin and melatonin levels, which change with the seasons. 

Serotonin is stimulated by sunlight, and therefore those levels drop in the winter when there is less sunlight and more darkness.  Serotonin is believed to play a significant role in SAD, as it is associated with both wakefulness and a sense of well-being. Day light – or lack thereof - in the morning helps set the internal clock, as it can be detected by the brain, even when sleeping.

A lack of sunlight to stimulate serotonin levels and help set our internal clocks can result in some people experiencing the “Winter Blues.”

Symptoms of Seasonal Affective Disorder can include:
• Drop in energy level;
• Fatigue, excessive sleeping;
• Difficulty concentrating;
• Irritability;
• Increased appetite (with carbohydrate cravings and weight gain);
• Sense of lethargy – wanting to hibernate;
• Antisocial thoughts – can’t be bothered to get together with friends or family.

Symptoms typically begin by late fall or early winter and end by late spring or early summer.

Approximately 3-5 per cent of Canadians are estimated to be experiencing SAD, with another 10-15 per cent feeling the ‘winter blues’, a milder form of the disorder. Women are twice as likely as men to suffer from SAD.

A good way to help combat the winter blues or SAD is to let the light in, particularly natural light.

If you’re wondering what the best kind of light to keep serotonin levels up are, see the differences in light values below.

Candle light at 20 cm
10-15 Lux
 
Street light
10-20 Lux

Normal living room lighting
100 Lux

Office fluorescent light
300-500 Lux
 
Halogen lamp
750 Lux

Sunlight, 1 hour before sunset
1000 Lux

Daylight, cloudy sky
5000 Lux
 
Daylight, clear sky
10,000 Lux

Bright sunlight
> 20,000 Lux
 
Keep your home – and your life – as bright as possible by keeping curtains drawn, sitting by the windows, and walking outside when the weather is nice and the sun is out.

Another idea is to purchase a light box especially made for light exposure therapy. These full spectrum light panels are stronger than ordinary office or household lighting, should provide 10,000 LUX of illumination, and omit white light. They are used by sitting a few feet away from the box for a prescribed amount of time—usually up to 45 minutes—every day.  

Light therapy treatment in the morning has been shown to be more effective. Discuss this option with your doctor, as eye disorders such as glaucoma, cataracts and detached retinas may not be compatible with light therapy.

Another way to help get combat SAD is to get regular aerobic exercise. Numerous studies have shown the positive influence on a person’s mood with regular exercise of 20 minutes to an hour a day, as exercise releases endorphins, also known as the happy hormone.

Diet has also been proven to play an integral part in overall health and wellness, including mood and serotonin levels. A diet rich in complex carbohydrates, including potatoes and whole grain pastas and bread, have been shown to boost serotonin levels as they help to pass tryptophan to the brain.

While all these options are a great way to help beat the winter blues, you should always speak to your general practitioner or family doctor if you’re experiencing symptoms of depression. 

Contribution by Susan Wild of West Park’s Seniors Mental Health Service