Fat and pimply? Depressed? Unable to sleep? It must be winter, season of gloom and hibernation.
The best thing the poet Shelley managed to say about it was: "If winter comes, can spring be far behind?"Trond Bratlid, a Norwegian who spends three months of the year in perpetual darkness north of the Arctic Circle, sees things differently: "Most of the population considers winter to be a relaxing time with few social pressures and a slower pace of life."
Bratlid, consultant psychiatrist at Asgard Hospital in Tromso on the 69th Parallel, speaks for a local population that knows only central heating and triple glazing.
It also knows, and Bratlid treats, midwinter insomnia, carbohydrate cravings and seasonal affective disorder (SAD) - all illnesses associated with winter.
But Bratlid urges caution in ascribing winter ills to elements beyond human control - in this case, light starvation, treatable with large doses of electric light during the winter months.
Dr. Stuart Checkley, a consultant psychiatrist at London's Maudsley Hospital, which has done much of the work in Britain on SAD, says there's a danger in believing light treatment is a cure-all. "A lot of people sleep more and put on weight as part of their bodies' annual rhythm. They shouldn't rush out and buy expensive lights."
He says SAD "touches a very small number of all the people who suffer from depression."
Chrystal Branch, 56, bought her lamps 10 years ago and says they've changed her life. A founder of the British SAD Association, she suffered deep depressions, guilt and weight-gain from October to March every winter for 15 years until she read an article about SAD and the possibility of treating it with doses of electric light.
"Having SAD is like being a plant: You wilt, so you crave food to boost your carbohydrate levels. Being exposed to light for a few hours can revive me for two or three days," she says. "When I get irritable and lethargic, my children tell me to charge up my battery."
SAD may affect up to 1 million Britons, according to the association, which has 1,000 members. Electric light is believed to help the condition because it reminds the brain that it's no longer night-time.
During hours of darkness, the hypothalamus - the part of the brain that controls mood, appetite, sleep, temperature and libido - produces melatonin. It's a kind of nighttime hormone that the brain should stop producing during the day. Unbalanced levels confuse the brain and sufferers become permanently jet-lagged - until springtime.
Midwinter insomnia, which seems confined to the very Northern Hemisphere, is also caused by a melatonin imbalance. Where SAD sufferers become lethargic, MI victims cannot sleep. Because of the lack of sleep, their melatonin production becomes disturbed. Bratlid hasn't established a clear trigger to MI.
Sufferers of SAD, which is widely researched throughout the world, have concluded that their condition is triggered by traumas such as hormonal imbalances, divorce or job loss.
Branch believes hers started after post-natal depression. "We used to think SAD affected mainly women, but with the recession we are hearing from more men and people of all ages," she said.
Lennart Wetterberg, a neuroscientist at Sankt Goran's hospital in Stockholm, is trying to chart a world map of SAD. "We find SAD at both poles, and we know it is absent from the tropics," he said. "However, there is also African sleeping sickness; it is not SAD, but our studies may help us determine its provenance."
Wetterberg claims light treatment improves the condition of 50 percent of sufferers within 10 days, whereas anti-depressant drugs sometimes only take full effect after three or four weeks.
New studies suggest winter depression other than SAD and MI may be linked to geomagnetic storms in the upper atmosphere. They reach a peak around the autumn and spring equinoxes.
A Scottish study last year found that psychiatric admissions peaked in the two weeks after storms. In the Northern Hemisphere, one of the most dramatic storms is the aurora borealis - "northern lights" - most visible during November and December nights in Scandinavia.
Weight gain is a frequent complaint during the winter. A study last year at the Human Nutrition Research Center at Tufts University in Boston established that seasonal changes in body composition - with women putting on weight around the waist while losing bone mass - could be triggered by hypothalamus signals.
Even people without SAD or MI have biorhythms, and it's believed there's still in humans an instinct to hibernate; animals going to ground in winter have higher levels of melatonin than in the summer.
But literature as much as science tells us that the uplifting season of spring, as Shelley hesitantly predicted, is only just around the corner.