Those head doctors, they have a term for the effect a lack of sunshine has on your physiology: SAD, or seasonal affective disorder.

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And finally, those who suffer from seasonal affective disorder (SAD) or other mental health conditions can find the darkness of winter especially difficult, making them less productive and interested in work.

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Seasonal Affective Disorder, or SAD, was first described and named by the South African psychiatrist Norman Rosenthal in 1984.

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