• depression that afflicts people only during the autumn and winter months
  (October-April)
• the cause is believed to be due to the shorter daylight hours in autumn and winter

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• 5% suffer from severe form of S.A.D.; 15% suffer more moderate symptoms
• more common in women than in men (4:1)

• feeling down, gloomy
• loss of energy
• withdraw socially
• carbohydrate cravings & increased appetite
• sleep problems
• normal daily functions difficult to perform
• difficulty concentrating & feeling alert

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• Winter Blues – similar, yet milder symptoms of S.A.D. - lack of energy, feeling sad or
• down but, the most significant difference is the ability to function.

• lack of sunlight in fall and winter
• reduces the production of serotonin
• signals brain to overproduce “hibernation hormone”, melatonin
• too much melatonin in day makes us sleepy, shortens our activity cycle
• Circadian Rhythms, an internal body clock, regulates daily activity cycles over a 24-hour period, and bright light signals are necessary to reset this body clock every day.
• lack of light causes the body clock to go ‘out of whack’; thus affecting sleep, making it difficult to wake up, or causing a person to fall asleep and wake up at inappropriate times

• antidepressant medications may be used alone or in conjunction with light therapy and changes in your diet – consult your doctor

• by reducing the amount of carbohydrates in your diet you will experience fewer symptoms of lethargy and may find reduced cravings for food which will reduce weight gain that frequently accompanies this illness

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• involves being exposed to bright light, (20 times brighter than normal light), under specific conditions
• daily treatment usually fifteen minutes to half an hour
• light sources are available in different forms; special lamps that you sit in front of in the morning, a light visor that you would wear as you would a baseball cap, or in the form of a pair of glasses

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• light therapy produces serotonin
• light therapy suppresses or reduces the amount of melatonin, (the hibernation hormone), produced during the day, which helps extend the activity cycle during the day, and allows for better sleep at night
• light therapy resets the body clock (Circadian Rhythms) when it gets ‘out of whack’, allowing for better sleep patterns

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• light therapy is found to have a therapeutic, anti-depressant effect in 70% of people with S.A.D.
• relief of symptoms commonly occurs within two weeks of beginning light therapy

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• there are a few mild side effects reported, which include but are not limited to: eyestrain, headaches, irritability and insomnia
• insomnia usually occurs if the treatment is taken too late in the day
• avoid self-diagnosis, as there are existing medical conditions that may interfere with light therapy
• consult your doctor if you suffer from eye problems or if you are taking medication with photosensitivity listed as a side effect
• studies show that light therapy cause no long-term side effects

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Mood Disorders Association of Ontario website:
www.mooddisorders.on.ca


University of British Columbia S.A.D. information page:
http://www.psychiatry.ubc.ca/mood/sad/index.html


The Society for Light Treatment and Biological Rhythms:
www.sltbr.org
www.apollohealth.com
www.healthlight.net
www.northernlighttechnologies.com

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