It is clear to me now what is happening -- why, for example, I found myself one day last week devouring a bag of Jujyfruits, then (immediately afterwards) a bag of gumdrops, and later that evening half a box of Mrs. Goldenberg's Peanut Chews before the sugar fit was finally quelled.

I am not talking about a more or less routine trip to the vending machine for the tiny little packets of candy that vending machines dispense -- the sort of casual foray we all (guiltily) make from time to time; I am talking about putting on a coat and heading out into the cold to the drugstore for a major, economy-sized feeding of no nutritional value whatsoever. Stop me, I thought, before I devour more.

Of course it's sick, and of course I was, the next day. Not, however, as might have been expected, with hypoglycemia (or hyper -- I can never keep these things straight), or even a stomach ache. The doctor said last week it was bronchitis, for which there seemed to be some empirical evidence, and after four days of heavy sighing, a course of antibiotics and three bottles of Robitussin, it is now in remission, though the critical phase has not yet passed.

Well, the doctor can call it bronchitis if he likes, but I know that the bronchitis is only a symptom of something far more profound, though something time itself will cure.

I was, I now know, suffering from my annual autumnal malaise which this year began, imperceptibly at first, at 4:33 p.m. Eastern Daylight Time on Saturday, Sept. 22, and had suddenly entered its acute phase the late afternoon of the sugar seizure. It is possible to date the subtle onset of the illness so precisely because it coincides with the autumnal equinox, the moment the earth tilts toward December, causing the sun to slip below the equator and the hours of darkness in our northern hemisphere to increase each day so that by late November most of us are going home in the dark and many of us are leaving in the dark, too.

This malady of life in the twilight zone, debilitating but not fatal, is called by its appropriate acronym: SAD, for seasonal affective disorder. "As the days grow shorter each fall," The New York Times reported a couple of weeks ago but which I neglected to read until yesterday, "people with SAD become sad, irritable, anxious, sleepy, socially withdrawn and uninterested in work and play. At the same time their appetite increases, they crave carbohydrates" -- that explains the Jujyfruits, the gumdrops and the peanut chews -- "and they gain weight." The fault, dear friends, is astronomical.

I haven't checked the scales, though I'm trying to kick the candy, but I am grateful to the scientists who earlier this month held a three-day conference on the biological and medical effects of light for giving my seasonal slump a certain legitimacy. The scientists have determined that -- like the plants and the lower animals -- we are creatures of the light, and photosensitive, maybe even phototropic. Sunlight turns off the release of melatonin in the pineal gland and darkness turns it on. Too much melatonin and you start reaching for Mrs. Goldenberg's Peanut Chews.

As I said, the malady is now in remission, which I attribute to a sunlit weekend and which the doctor ascribes to antibiotics, but the danger is not yet past. Everything will be okay, however, shortly after Dec. 21. That's the day of the winter solstice, when the earth takes another tilt on its axis and shortly thereafter the sun begins to rise higher in the southern sky and the light lasts longer. Until then, I'll keep the candy handy. Maybe I should have been a druid.