Perhaps we ought all to be in sparkling form as we look forward to the coming yuletide and millennium. But for some,
The melancholy days are come, the saddest of the year,
Of wailing winds and naked woods, and Meadows brown and sere.
The dark, dull, dreary weeks of winter bring 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 melancholy allegedly associated with lack of sunlight during the winter months. The link is the tiny pineal gland at the centre of the brain, which inter alia produces a hormone known as melatonin. The gland is triggered into action by light, whose presence or absence it detects by means of signals received from the eye: darkness prompts it to secrete "the Dracula hormone", as some people call melatonin, and light is a signal for it to stop.
An excess of melatonin, some allege, predisposes people to depression. Women are said to be more vulnerable to SAD than men, and people living in northern latitudes, and those below the age of 30, are more likely to be victims than the remainder of the population.
The antidote for SAD is simply light. SAD people seem to cheer up when exposed to strong artificial light for six hours or so per day; apparently it makes their bodies think that summer has come round again, and their depression lifts. And for those who cannot spare the time to sit beneath an artificial sun for more than half their working day, a relatively recently discovered drug called Sertraline is also alleged to alleviate the symptoms.
But there are experts also who maintain that SAD does not exist at all. They argue that the symptoms of SAD - a general lethargy, sadness, disturbed sleeping patterns and a loss of appetite - are common to all kinds of clinical depression, and that it cannot be specifically isolated from other ailments.
They prefer the old idea that we all just have good days and bad days; on the bad days we can do little else but tolerate our misery, and understandably, bad days in this context are usually more common during the winter.
One sceptic noted unsympathetically that "on the average winter day, the average person feels a little worse than average anyway", although few go as far as the American doctor who described SAD as being "the last refuge of the hypochondriac".