Seasonal Affective Disorder (known widely by the appropriate acronym - SAD)  is a form of clinical depression associated with late autumn and winter and thought to be caused by a lack of light. It’s estimated to affect 10 million Americans, with another 1-2 million Americans suffering from a milder form, often referred to as 'the winter blues' - making it extremely common, affecting 1 in every 30 people in the United States.

The signs and symptoms of SAD are almost identical to those of clinically diagnosed major deppression with the difference being that those affected by SAD generally experience a gradual worsening and then resolution of their symptoms as the seasons change and with them the amount of light and sun exposure. 

Symptoms of SAD

• Feelings of Sadness and Despair
• Irritability
• Crying Spells
• Poor Sleep
• Tiredness & Fatigue
• Body Aches
• Trouble Concentrating
• Lack of Motivation
• Loss of Sex Drive
• Overeating & Associated Weight Gain

Facts About SAD

• Estimated to affect 10 million Americans (almost 1 in 30)
• Five times as many people diagnosed with SAD than cancer last year
• The term 'Seasonal Affective Disorder' was coined in 1985
• SAD is more common the farther North you live (prevalence is 9.7% in New Hampshire, only 1.4% in Florida)
• SAD typically starts around age 20
• Sufferers much more likely to be women (60-90%)
• Symptoms tend to be much more severe in men, however
• There is no specific diagnostic test for SAD - it is diagnosed using patient's history of depressive episodes
• SAD has been seen to run in families so there may be a genetic component to the illness
• Researchers believe SAD to be caused by a combination of lack of light exposure as well as vitamin D deficiency from lack of the sun's rays on the skin

Myths About SAD

• Anyone experiencing a lack of energy or other negative change associated with seasonal change is suffering from SAD
• Sad sufferers are sad for the entire winter (variations in symptom severity occur as the seasons progress)
• SAD only occurs in the winter - a less common variety affects people in Spring and Summer causing symptoms such as mania and aggression
• Bright Light Therapy is the only effective treatment

Treatments For SAD

• Bright Light Therapy
• Temporary or Permanent Relocation to Sunnier Climes
• Psychotherapy & Counselling
• Vitamin D Supplementation

Further Information About SAD

Much of the information in the post were taken from the YellowBrick website where you can find a large amount of facts and figures about SAD with some excellent infographics at http://www.yellowbrickprogram.com/seasonal-affective-disorder.html. YellowBrick are a residential and out-patient treatment center for those suffering from mental illness and addiction. Along with information on their website they have produced a PDF document containing some excellent information for SAD suffers - Shining Some Light on Seasonal Affective Disorder (SAD).