Nurse practitioner Kimberlee Lonergan from Sleep Medicine Northwest answered your questions about seasonal affective disorder (SAD) and light therapy.
For more information, see the story, "A light box can brighten your darker days — when used correctly"
I just bought an "uptime" day light box that is UV free. Do UV rays help produce beneficial "natural" light? There seems to be a variety of opinions and studies supporting each theory camp.
— Frey, Seattle
Kimberlee: You are right. There are a variety of opinions out there. Generally speaking, the light boxes available are made with either broad- or full-spectrum bulbs which closely emit the UV and visible-light spectrum. The UV is shielded with a Plexiglass diffuser and should be UL tested for safety. UV in sunlight is important for Vitamin D metabolism.
I don't have the space or budget for a "light box." What do you think about the new Ceramic Metal Halide by Philips? This is full-spectrum with 85 percent CRI (color rendering index). The 400 watt-light produces 6000-foot candles at one foot.
— Kevin, Seattle
Kimberlee: Have you been diagnosed with SAD or are you suffering from the lesser symptoms such as difficulty waking in the morning, daytime fatigue, carbo craving etc? It is important to know what you plan on doing with this bulb. The halogen-coated lights are supposed to put off less heat but more intense light. You should put this light bulb in a metal reflector and put on a timer and direct it toward the ceiling behind your bed. This may help to wake you in the morning and reset your body clock during the winter. Talk to the folks at the Indoor Sun shop in the Fremont district in Seattle. They have inexpensive supplies and the knowledge to help you with this. A CRI of 85 or above is adequate. Be careful!!
How do I know if I'm being affected by seasonal affective disorder?
— Caryn, Woodinville
Kimberlee: There are about nine basic areas affected by those suffering from SAD. Sleep is increased, energy is decreased, concentration is more difficult, craving for carbohydrates is increased, mood is low, feelings tend to be more negative (loss of self esteem), libido tends to decrease, anxiety increases and people tend to withdraw socially. You should see a health care practitioner for evaluation.
I live in a very sunny state, but during the summer months I feel very lethargic and lack ambition or even the ability to think straight. Could this be a summer SAD?
— Connie, Austin, Texas
Kimberlee: Yes, this could be a seasonal variation of SAD. We don't have a lot of research on this variant. I would suggest that you talk with a psychiatrist who might help to diagnose you. Sometimes light is used to treat this, and other times a combination of light and medication such as an SSRI (selective serotonin re-uptake inhibitor, a variety of antidepressant), depending on your symptoms.
Is SAD more pronounced in people who are more accustomed to higher light levels, such as a person who has relocated to Seattle from San Diego or another sunny place? Or are sufferers more likely to be from areas with dark winters?
— Erica, Edmonds
Kimberlee: The prevalence of SAD is higher in northern latitudes and lower as one approaches the equator. The incidence of SAD in San Diego is about 3 percent and in Seattle it is closer to 10 percent to 15 percent, not including those with subsyndromal SAD (those affected to a lesser degree), which approximates 30 percent. Relocating to an area with shorter daylight disrupts the regulation of many hormones and neurotransmitters responsible for mood, energy, etc. This may have to do with retinal sensitivity to light which varies from person to person. Vacation to San Diego in the winters, and this may help.
Do you think these lights would be good as a preventive measure? I never felt like I needed one and actually enjoy winter, but is there any evidence that they "help" people who aren't depressed, or know they're depressed?
— Sara Jo, Seattle
Kimberlee: No, I would not recommend lights as a preventative measure. The best thing you could do is to get outdoors. Even on a cloudy day in the middle of winter, the intensity of the sun is about 10,000 lux. Take a one-hour walk, and you get about the equivalent of 30 minutes in front of a 10,000-lux light box. Plus you get the benefit of getting Vitamin D.
I have anxiety disorder and have noticed that the more sun I get the better I feel. I also get this strange feeling about 5-7 p.m. if I lay down and watch TV. It feels like tension overwhelms me, and I have to get up and go outside. Do you have any ideas what could be bothering me? I take a little Klonopin and Ambien to sleep at night. Thanks.
— Dan, Seattle
Kimberlee: Chronic anxiety can decrease serotonin which is an important neurotransmitter for feeling good. One theory about getting bright light is that it increases serotonin and helps you feel better. There are many reasons for anxiety and insomnia. I suggest you have an evaluation at a sleep-disorder center or with your doctor or psychiatrist to discuss this. Klonopin is a very strong anti-anxiety agent and is also used for panic disorder as well as many other things. Ambien is a nonbenzodiazepine which is used to facilitate sleep.
What about the use of a light box in conjunction with antidepressants. Any thoughts?
— JK, Seattle
Kimberlee: In certain situations this is beneficial. For instance, if light therapy alone is not helping with the symptoms of winter depression, then adding an antidepressant has been shown to be helpful in alleviating symptoms.
My question is what kind of light bulbs to buy, how expensive are they, where to get them inexpensively?
— Susan, Seattle
Kimberlee: There is a good source called
www.topbulb.com. The consensus is that it does not really matter whether you buy full-spectrum or broad-spectrum or fluorescent tubes. Anecdotal reports suggest that full-spectrum bulbs may make people feel better because the light we see from them is in the bluer range like that of sunlight. Scientifically, this has not been proved to be more effective over bright white light. Fluorescent tubes in the cool blue range would be your cheapest and would work fine if you are trying to replace bulbs in your home or kitchen.
When I was a student at UW in the early 80s, I suffered mildly from SAD and took care of it by replacing one of the light bulbs in my two-bulb ceiling fixture with a black light bulb. It made all the difference, and the effect was immediate. The idea came to me intuitively, and I used it for several winters after. Later I switched to D-50 (daylight-spectrum fluorescent) lighting, but mainly for artistic color-rendition purposes. Now daylight-spectrum bulbs (like the 'GE reveal' bulbs) are widely available. So I believe for many people there is no need to buy expensive light boxes. Just using one black light bulb in the living space or daylight spectrum bulbs would do the trick.
— Chris, Seattle
Kimberlee: If one is truly suffering from the debilitating symptoms of SAD, then chances are that one light bulb will not be of help.
Doesn't anyone ever write and say that they get all those depressive symptoms with the approaching summer months? With all that extra bright light? Are researchers interested in the people that turn into irritable, crabby, carbohydrate cravers in the summer months and can't wait for the return of cool, rainy, cloudy weather? I try to remedy my symptoms by drawing all the shades and going to a dark, cold room. That's is the only way I can shake off the miserable feeling that "I hate summer." It gets worse as I get older. What are the researchers comments on that scenario?
— Cheryl, Renton
Kimberlee: This is interesting and not well researched yet. There are variants of depression. People with bipolar illness for example can have episodes of hypomania or mania which can include insomnia, agitation, irritability, difficulty concentrating, focusing, poor impulse control etc., which may be more pronounced in the summer and with increased sunlight. Light therapy can trigger this if someone has bipolar illness or if one uses light therapy inappropriately. When winter returns, there tends to be more depressive symptoms. I would talk with your health-care provider or psychiatrist if these symptoms are bothersome to you.
At least one study showed that taking vitamin D was more effective than a light box for Seasonal Affective Disorder (SAD). It's a lot less expensive and easier to administer. There are many interesting new insights coming out on vitamin D which would be especially helpful for Seattle residents.
— Tom, Seattle
Kimberlee: Thanks for the info. Getting outside is still the best source!!
This is the second season I've been using the Apollo GoLite, the only light box that I could tolerate. I had tried the regular-size box from three or four different companies. My primary question is regarding eye safety and the very portable GoLite. The Apollo Web site has very impressive statistics about Bluewave and impressive claims about ocular safety with references to the federal Food and Drug Administration (FDA) and the National Institutes of Health (NIH). Can I rely on these claims? My second question is that I keep experimenting with the portable box and haven't yet discovered the optimum time of day and amount of exposure. I'm actually getting too sleepy, which probably means too much serotonin. Should I stop using the box for more than a day before trying to experiment again with timing to get back to my normal SAD baseline?
— Lin, Tacoma
Kimberlee: To answer your question, there is not enough scientific evidence to provide a recommendation on using the GoLite with the blue-light wavelength. Since it is a more potent suppressor of melatonin (the hormone of sleep) it may also be more potent in terms of eye damage. While it is an interesting treatment (uses a very narrow band in the blue wavelength), the jury is still out.
To answer your next question, the best time of day to use your light box is in the morning. Morning light is superior to evening light in terms of the phase-shift hypothesis. Most people with SAD tend to be sleepy, have trouble waking in the morning (lower body temperatures) and are sluggish during the day. This has to do with the timing of melatonin and this is controlled by light and the master body clock or suprachiasmatic nuclei (SCN). Bright morning light with a 10,000-lux light box at the prescribed distance for 30 minutes has been researched and validated to show that the timing of melatonin can be shifted or advanced earlier, help with sleep onset and waking earlier in the morning.
If I want to build a light box, how many 100-watt light bulbs will give me 10,000 lux? And how far away do I sit from these bulbs?
— Bryan, Montreal, Canada
Kimberlee: This is not recommended. It is too difficult to build a light box with the amount of lux needed and provide safety to shield out the UV rays. Most light are UL (Underwriters Laboratories) approved and have undergone safety testing to meet specification and industry standards.
Is using plant lights equal to using a light box?
— Catherine, Lynnwood
Kimberlee: No, not the same at all.
Does the time of day that one uses a light box make a difference?
— Debra, Seattle
Kimberlee: Yes, morning light is best!
I just bought a light box but I'm having a hard time getting myself out of bed in the morning in time to use it. How about if I do a 20-minute session right after I get home from work?
— Jack, Seattle
Kimberlee: No, that will keep you up later at night and further shift your body circadian rhythm and timing of melatonin later. Set your alarm for the same time each morning. The more you do this and get up to use the box the better you will start to feel. This may take a week or two. If this does not work then you can try a dawn simulator.
Two questions: I am looking for a specialist that treats sleep problems (waking too early using light therapy). Where should I look? How does Blue Light therapy compare to the bright white light therapy? Thanks.
— Raymond, Renton
Kimberlee: Sleep specialty clinics are in every major city now. Here in the Seattle area and on the Eastside, we diagnose and treat a variety of sleep problems. I work at Sleep Medicine Northwest in the Northgate area and in Woodinville. We have Dr. Mazeika, Dr. Park and myself. You can visit our website
www.sleepnw.com. Please see earlier e-mail answer re: the blue light therapy. Thanks.