State of affairs

of intensity of light), and sit near it for 20 minutes to help chase away her blues.

Many people report depression with the onset of winter. Gliddon is one of millions around the world diagnosed with seasonal affective disorder (SAD).

From late autumn to late spring, when daylight is at its scarcest, SAD can affect people’s energy, mood, creativity and productivity and, in more severe cases, it can bring on major depression.

Lack of light, researchers say, can fool the body into making too much melatonin, which regulates the sleep-wake cycle. A person’s circadian rhythm simply gets out of whack.

It also depletes levels of serotonin, a neurotransmitter that regulates moods.

Scientists are almost unanimous in labelling SAD as a specific form of depression, though a journal study published recently by Norwegian researchers cast a sceptical light.

The study looked at the population in northern Norway over two winters and determined that there was no ‘‘spontaneous complaint’’ of depression during the dark months.

But Robert Ruxin, a psychiatrist with the giant Amer- ican healthcare provider Kaiser Permanente in California, has no doubts about SAD.

‘‘We see people who really don’t have any mood issues the majority of the year and tend to have issues every winter,’’ Ruxin says. ‘‘And then there’s people with chronic depression who tend to have more trouble in winter than the rest of the year.’’

Among the treatments for SAD are cognitive behavioural therapy, medications to boost serotonin and melatonin levels, and light therapy.

Gliddon has seen the light. She says her full-spectrum light box has made all the difference.

‘‘If you don’t want to do something chemical, this is a really big help,’’ she says. ‘‘Prozac alone wouldn’t do it for me. I need the light therapy.’’

An early adopter of light therapy, Gliddon purchased her lamp nearly 20 years ago from a Canadian company. She remembers paying nearly US$1000 for it. In recent years, as studies have confirmed the effectiveness of light therapy, the lights are more widely available and much cheaper.

‘‘It’s very bright,’’ she says. ‘‘I crochet the whole time, or read the newspaper. I don’t think I could just sit there doing nothing. But it’s important the light hits your retina. So you don’t want the light on with your back to it.’’

Gliddon is so often quick with a joke and a kind word that it’s difficult to imagine her as grumpy and lacking motivation. But she’s had her moments. ‘‘You just start slowing down and want to sleep and eat more. You react like it’s night time when it’s really only 5.30pm.’’

Now, she’ll open the shutters in her house, turn on all the lights and, each mid-morning, bask in the glow of her fullspectrum light.

‘‘I never skip a day,’’ she says.