STEVE INSKEEP, host:
It's MORNING EDITION from NPR News. Good morning, I'm Steve Inskeep.
This day is the winter solstice - a fancy way to say that it's really dark. It's the shortest day and the longest night of the year. And in Your Health this morning, we'll find out if there might be an upside to darkness. First, we have some treatments for the wintertime blues.
NPR's Allison Aubrey reports.
ALLISON AUBREY: If you've ever watched an alligator or lizards bask in the sun, the reptiles can be completely motionless until they're all warmed up and jump into action.
Andre Pennycooke can relate. The 33-year-old graphic designer craves bright sunshine. Without it he feels lethargic, something he first realized when he moved from Miami to New York 15 years ago.
Mr. ANDRE PENNYCOOKE (Graphic Designer): It took me a while to get aware of it. I mean, first I thought it was just being depressed being away from home, being in college. And then as it progressed year by year, it was really my friends who pointed it out to me, that at a certain point I became depressed, and I'm always low in energy.
AUBREY: October is that certain point in the year when Seasonal Affective Disorder, or SAD, starts to kick in. And by late December and January, it's more pronounced.
Pennycooke is not alone. Experts estimate about five percent of adults in the U.S. have this type of seasonal depression. To beat his blues, Pennycooke creates his own sunshine. He uses a therapeutic light box to replace what the Earth's winter tilt has stolen away.
The light box, which gives off an intense outdoor sort of light, sits on Pennycooke's desk. Every morning he turns it on while he's making his cereal.
Mr. PENNYCOOKE: And I sit for about 45 to an hour in front of the lights while I'm in, you know, doing bills, reading a paper, listening to the news, and that sort of thing. That's my morning ritual.
AUBREY: Research suggests that sort of light therapy significantly helps about 50 percent of the people who try it. For those who don't have a half hour to sit in front of the light box before work, a newer adaptation of the treatment is called Dawn Simulation.
Andre Pennycooke has tried this, too, as part of a clinical trial at Colombia University.
Mr. PENNYCOOKE: Dawn simulation starts out where you're sleeping, as you normally do. And it's on a timer, it's a light on a timer, and at around 5:00 in the morning, it slowly comes on; the light gets brighter and brighter.
AUBREY: Producing the equivalent of a spring sunrise in your bedroom. Pennycooke says the gradual increase in light has the effect of gently nudging you awake. And since a big part of the problem with seasonal depression is that people sleep too long, this is helpful.
Michael Terman is director of the Center for Light Treatment at Columbia. He says with dawn simulation the mere exposure to light sends a signal to the brain that helps reset your internal clock.
Mr. MICHAEL TERMAN (Director, Center for Light Treatment): You can sleep through it, but your brain is definitely seeing the signal.
AUBREY: The signal while you sleep, however, is not as strong as a half-hour in front of the bright light box. Pennycooke says while dawn simulation did help him wake up earlier, he prefers the light box. His experience dovetails with research that shows the more intense light therapy works best.
For those who don't respond to light therapy at all, Terman is also investigating a treatment that was considered wacky a decade ago. It's called negative air ionization.
Andre Pennycooke, who tried this one too as part of the Colombia study, says he was very skeptical when he learned the treatment was nothing more than a small bedside device that blows a stream of charged ions towards you while you sleep.
Mr. PENNYCOOKE: When it clicks on, it just makes some nice little hissing sound, not too loud. And it blows a little air. It's not imposing at all.
AUBREY: So he didn't expect much. But Pennycooke ended up being one of the 48 percent of people in the study who seemed to benefit from negative ions. In order to figure out whether the positive effect was really from the negative ions and not just an expectation among the participants, Terman tested two kinds of devices.
One device blew out a weak stream of ions. The other device delivered a high concentration. None of the participants knew which machine they were using, which was an important comparison to do, according to psychologist Kelly Rohan of the University of Vermont. She was not involved in the study, but she did review the evidence.
Ms. KELLY ROHAN (University of Vermont): I think the data are fairly compelling that the activated negative ion generators are more effective than a deactivated one. As a scientist, it's hard to argue with data. So I think there is something to this therapy. I think what's unclear and unknown is exactly how or why it's working.
AUBREY: That lack of any clear mechanism means that for a good reason there will be lots of skeptics. For now, that 30 minutes in front of the light box is still the recommended therapy for seasonal depression.
Allison Aubrey, NPR News, Washington.