/ that time of year again in Britain , 6.00 a.m. in the morning and it is still very dark. The autumn equinox has passed
and the hours of daylight are decreasing rapidly, this will continue until December 21st the shortest day of our year ,
after that the light will increase gradually peaking on June 21 next year.
Enter SAD seasonally affected disorder, or lack of daylight,
SAD () is a type of winter depression that affects an estimated
7% of the UK population every winter between September and April, in particular during
December, January and February.
It is caused by a biochemical imbalance in the hypothalamus due to the shortening of daylight hours and the lack of sunlight in winter.
For many people SAD is a seriously disabling illness, preventing them from functioning normally without continuous medical treatment.
For others, it is a mild but debilitating condition causing discomfort but not severe suffering. We call this subsyndromal SAD or 'winter blues.'
It is estimated that a further 17% of the UK population have this milder form of condition.
