What is the difference between seasonal affective disorder (SAD) and depression?

At first glance, it may seem like seasonal affective disorder and depression have few differences. After all, SAD is a type of depression, with symptoms including lethargy, low mood, a loss of pleasure in things you used to find enjoyable and feelings of despair or worthlessness – all of which are signature symptoms of depression. Underneath, however, are subtle differences.

“SAD is a type of depression that tends to come and go in a seasonal pattern. This can also be known as ‘winter depression’ or ‘winter blues’ because symptoms are usually more evident during the winter months,” says Eugene Farrell, mental health lead for AXA PPP Healthcare.

“The typical symptoms start as early as August and are usually at their worst from November to February, tending to disappear by April time. SAD can be caused by a lack of light during winter when days are shorter with less sunshine, and the sun is not as bright. However, reduced light levels could bring on the symptoms of SAD at any time of the year, for instance, prolonged periods of dull weather in summer.”

Seasonal affective disorder and depression - what’s the real difference?