When Norman Rosenthal moved from Johannesburg to New York City for a psychiatry residency, he found the winters dark and gloomy. It wasn’t until a few years later that he realized the winters might be more than just gloomy. Working in a psychobiology lab in the early ’80s, he tried an observational experiment on an engineer who he knew had bipolar disorder and depression and had had mood swings from mania into sadness for many years. The engineer had kept a log of the changes in his notebooks; it was clear he was typically depressed as the days started to get shorter after the solstice, and then into fall and winter. Rosenthal and his colleagues wondered if light might be able to help, particularly with a stronger exposure than what he’d been getting in office buildings. “We took a rectangular ceiling fixture that had fluorescent lamps in it and rigged it up to stand horizontally,” says Rosenthal. It was a highly primitive light box. Being able to get up close to the source did the trick. With the help of bright lights, the engineer came out of his winter depression, Rosenthal recalls: “It was like watching a law of nature unfolding.”
It is practically common knowledge today that the darkness of winter can make you more depressed than you were before. But back in the ’80s, Rosenthal and his colleagues had to prove it. So they put a notice in the Washington Post, seeking people who had winter mood swings. Twenty-nine fit their criteria and lived close enough to come into their lab for diagnosis and light therapy. In 1984, they published the paper that first described seasonal affective disorder, or SAD. When I spoke to Rosenthal, he was sitting in his office, two large sunlamps bathing him in light.
Who needs a sunlamp? “Many, many more people than you might think,” says Rosenthal. Though SAD is thought to affect a small percentage of the population, people without a clinical diagnosis often aren’t functioning at their full capacity in winter, either, he explains. He knows this because people come into his lamp-illuminated office and feel better. He sees the trend everywhere: A friend in Toronto built a sunroom with large windows, and now it’s their favorite place to hang out. When I lived in (and worked from) a room with a window that was mere feet from a brick wall, my dad mailed me a SAD lamp.
I turned it on in midday, for indiscriminate amounts of time, in defiance of the instructions (half an hour a day after waking up, sitting a foot away). I couldn’t help it; it was as though my tiny Brooklyn room were suddenly located on a beach. That lamp was pretty large, with kind of stadium-light vibes. While Rosenthal argues for larger lights, as those are the ones that have been used most in studies, the ones in his office are a little bit smaller, a foot-by-a-foot-and-a-half. (He has two.) If you want a large lamp, try Wirecutter’s recommendations; its top pick is the lamp I used previously, and I found it a little less cumbersome when removed from the stand.
But I’ve found that I’m just more likely to keep a smaller lamp sitting out, and therefore, I’m more likely to use it. The Verilux HappyLight, which is the size of an iPad, is what I use today. It sits unassumingly on my windowsill, and is 10,000 lux, which Mayo Clinic psychologist Craig Sawchuk advised me was the most important part. (Most of them are this intensity, but if you get one with a lower intensity, you just need to use it longer to get the same effects.) For me and my inconsistent, nonclinical use of the thing, this is handy. If you’re dedicated to a regular routine and you travel, having an even smaller lamp might be crucial. One company in Sweden made a light therapy system that’s designed around convenience—it comes as earbuds that shine light through your ear canals and, they claim, into your brain. The iPod-like setup is $200, and while there’s a study that suggests they work, it lacks a control group and was funded by the company that makes them. That is also pretty expensive for a light therapy device: Lamps cost as little as $30, and even a very nice, large one can be had for a little over $100.
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Despite all the intuitive benefits of light (shining into your eyeballs, at least), whether a sunlamp will be truly helpful for those of us without clinically diagnosed seasonal affective disorder is hard to say. In a pilot study of 54 patients hospitalized for burnout (yes, really), light therapy improved a slew of things: emotional exhaustion, cynicism, and a sense of accomplishment, as the authors write. That said, other small studies on patients with less severe burnout have been inconclusive. And while light therapy didn’t affect the overall depression scores in that pilot study (people with seasonal depression were explicitly screened out) an earlier meta analysis concluded that it might have some positive effects for folks with depression nonetheless.
Like so many things in this world, whether you will benefit from a sunlamp is highly individual. The side effects are minimal, limited to headaches and maybe feeling a little too awake if you use it late in the day (though if you have more than mild mood shifts, check in with a doctor before you experiment). Rosenthal points out that you can basically do your own experiment, using the lamp for a few weeks within a company’s return window. Not a bad deal for having your own personal home star.