Winter Darkness, Season Depression
Winter depression is still a mystery to scientists who study it. But researchers agree that people who suffer from seasonal affective disorder are particularly sensitive to light, or the lack of it.
Arctic Winters continued...
He stays active in winter, so "cabin fever" isn't a
problem for him, either. "If you sit around the house
and do nothing all day I suppose it could eat at you," he says. "But
there is always something for me to do -- snow-machine, cut firewood ... or
just going into town and have a cup of coffee with friends at the
"There are people, though, that will
have a ten-yard stare in a five-yard room," he says. Some seek
comfort from a bottle, too. "In lots of the smaller
villages, that does happen. Drinking is a big problem."
Seasonal affective disorder researcher Michael Terman, PhD, at
the Columbia Presbyterian Medical Center in New York, offers some possible
explanations for why seasonal affective disorder isn't more common in the
arctic. For one, people with seasonal affective disorder may be genetically
predisposed to clinical depression and light sensitivity. Most people, in any
place, wouldn't have both genetic traits. "Another way to look at it is
that those are the people who are still in Alaska," he says. People who
can't cope might not stay.
But not everyone affected by seasonal changes has full-blown
seasonal affective disorder, so estimates of how many people do have it may be
low. "Winter depression is a spectrum of severity," Lewy says. You may
have trouble getting up, have bouts of fatigue during the day, or feel
compelled to overeat, without feeling depressed.
These symptoms can be treated with the same therapy given to
seasonal affective disorder patients. Bright light -- generated by a special
light box that's much brighter than a normal lamp -- is the first option. It's
proven to work, but not for everyone. Also, the right time for it differs from
person to person, Terman says. For a night owl, taking light therapy too early
could make seasonal affective disorder worse.
om Wehr, researcher at the National Institute of Mental Health,
has proposed a new explanation for seasonal affective disorder: It may stem
from too much melatonin. When the brain's pineal gland starts pumping out
melatonin, we get sleepy. During winter, animals secrete melatonin for longer
periods than they do at other times of the year. Wehr discovered that people
do, too -- but only those who suffer from seasonal affective disorder.
Light therapy would still work if melatonin were the main
culprit, because light controls melatonin levels. Researchers are also testing
a drug called propranalol, which they hope will improve seasonal affective
disorder symptoms by curtailing melatonin flow in the morning hours. Lewy is
studying the effects of small melatonin doses given in the afternoon, hoping
that they will adjust circadian rhythms.
Raymond Lam, MD, researcher at the University of British
Columbia, Canada, and others are studying the role of brain chemicals like
serotonin and dopamine. "We know there are interactions between the
serotonin system and the circadian system," Lam says.