HAVE you ever felt sad, dejected and depressed around this time of year and not known why?
It could be just "post Christmas blues" and, in any event, it is natural enough to feel under the weather now and then in the dark, dull, dreary weeks of winter, only to perk up again with the coming of the brighter days of spring.
Wintertime, however, brings to a small but significant sector of the population a sense of deep depression quite outside the normal range of tolerable discontent, a condition which since about 1980 has been identified by name. It is known as Seasonal Affective Disorder SAD for short.
SAD is a form of chronic depression, new by name if not in nature, allegedly associated with lack of sunlight during the winter months. The key to its occurrence, apparently, lies in the tiny pineal gland at the very centre of the brain which produces, inter alia, a hormone known as melatonin.
The gland is triggered into action by light, the presence or absence of which is detected by means of signals from the eye. Darkness prompts it to secrete the "Dracula hormone as melatonin is sometimes called, and light is a signal for it to stop.
An excess of melatonin predisposes certain people to depression too much of it and they just cannot cope with winter any more.
SAD is difficult to diagnose specifically, because its symptoms a general lethargy, disturbed sleeping patterns and a loss of appetite are common to all kinds of clinical depression. Once identified, however, the remedy is simple.
SAD people cheer up when exposed to strong artificial light for a number of hours each day. It makes their bodies think that summer has come around again and their depression lifts.
At first it was assumed that the light used for SAD treatment would have to imitate the sun, with lots of blue green provided in the full spectral mixture of colours and containing less red orange than is found in ordinary domestic artificial light.
More recent research, however, suggests it is the intensity of the light that is important the body reacts positively to any kind of artificial light, provided it is strong enough.
The vast majority of us, however, have no such simple solution to our winter blues. On our bad days, we can do little else than tolerate our moody misery and think of Longfellow
Be still, sad heart, and cease repining,
Behind the clouds is the sun still shining
Thy fate is the common fate of all,
And into each life some rain must fall.