Seasonal Affective Disorder

Seasonal Affective Disorder (SAD)

Seasonal affective disorder is a type of depression that is due to a lack of exposure to light during the winter. It begins in the autumn (usually October or November) and subsides in the spring (usually March or April). SAD is rare in the tropics, but is measurably present at latitudes north of 30°N, or south of 30°S.

Incidence of disease in Ireland:

In Ireland, seasonal affective disorder may occur in up to 20% of the population. (Clare, 2010) Women are more likely to suffer from seasonal affective disorder than men. It is thought to affect 2 million people in the UK and Ireland and over 12 Million people across Northern Europe. Historically we only ever worked outdoors. Two hundred years ago 75% of the population worked outdoors now less than 10% of the population work in natural outdoor light. Whilst this is fine in the Summer months when there are longer daylight hours, in the Winter months, people tend to go to work in the dark and go home in the dark and don't get to enough natural daylight. (www.sad.org.uk, 2008-2010)

Classification of SAD:

Seasonal affective disorder is classified as a mood affective disorder. It is a type of depression that occurs each year at the same time, usually starting in autumn or winter and ending in spring or early summer. SAD is seen not as a condition in its own right but as a subset of major depressive or bipolar disorders. It is more than just "the winter blues". A rare form of SAD known as "summer depression," begins in late spring or early summer and ends autumn.

Symptoms of the disease:

There are a diverse range of symptoms of SAD. Many are associated with a feeling of general depression, which is why it is sometimes known as the 'winter blues'. SAD can be a serious disorder and may require hospitalisation. The symptoms of SAD mimic those of dysthymia or clinical depression. At times, patients may not feel depressed, but rather lack energy to get out of...