Seasonal Affective Disorder (SAD)
In 1979, Dr. Norman Rosenthal moved from his home in South Africa to New York. Over a short period of time he found that the short days, compared with those in South Africa, were affecting his energy levels, and that these feelings would usually persist until spring. In 1984 at the National Institute for Mental Health, this one doctor's brush with seasonally induced depression began the study of what is commonly called winter blues, or more clinically, Seasonal Affective Disorder (SAD).
What is it and who gets it?
Affecting approximately 5% of the US population SAD is a seasonally induced depressive disorder that manifests itself during the darker months of the year, typically between October and April, with symptoms often completely abating shortly thereafter. A person with SAD has problems responding to the seasonal changes in light. Though nearly anyone can potentially be affected, the prototypical SAD patient is a woman in her 20's or 30's living in a far northern climate experiencing feelings of anxiety and fatigue.
In order to meet the clinical definition of suffering from SAD, a person must exhibit the symptoms through two consecutive winters. (Morano, 2003)
Americans are more than twice as likely than European to have SAD. This can be the result of several factors, including cultural response biases, genetic differences, seasonality and climatic variations. (Lam, 2002) Women are also more than 4 times as likely as men to exhibit symptoms of SAD. (Hardy, 2004) Children of SAD sufferers are also likely to suffer from SAD, as this order is believed to be genetic, and hereditary.
SAD definitely has a stronger prevalence as you move into northern climates, but studies have only shown this prevalence to be modest (Lam, 2002).
SAD tends to generate a 'hibernation-like response' (Morano,