I am 60 years old. For 16 years I have successfully treated my Seasonal Affective Disorder (SAD) with light therapy and a low dose of Paxil.  My first signs are anxiety, sleep disruption, and social withdrawal.  This year the light therapy is not working, and I am a mess from depression and anxiety.  Does light therapy become ineffective?  I have tried changes, and new, clinically approved lights, with no help.  Any thoughts?

Sorry to hear that you’ve been having trouble maintaining good effect from your light + medication regimen. There could be numerous reasons, unfortunately impossible to sort out from the limited information in your note.  You give one possible clue, however, when you mention “low dose of Paxil.” Both meds and light lie on dosing dimensions, which can be manipulated separately or in concert.  Dosing of light involves three main factors: level of illumination at the eyes (lux), duration of the daily session, and timing of the session relative to your circadian rhythm. Take (or re-take) our Morningness-Eveningness (AutoMEQ) questionnaire to see if your treatment schedule is a good match to your rhythm. Consider increasing session duration in modest steps of about 10 minutes, with four days at each step to ascertain effect.  You should not go beyond a 60-minute session.  Make sure your sitting position at the light box is correct for receiving full 10,000 lux exposure.  If your doctor is recommending a Paxil dose increase, it is very important to do this in coordination with light dose adjustment, or you may start experiencing side effects.

Loss of effect may also be due to progressive eye problems typical at your age, so you should have a thorough ophthalmology check-up, and you should discuss your experience with light dosing with your ophthalmologist. If these steps don’t produce results, it will be time to seek a psychiatry consultation to probe other factors that may have led to this year’s turnaround after your years-long positive experience.

I’ve been using light therapy for SAD for about a month and have found it tremendously helpful for my mood. I suffered with SAD for about 6 months out of the year during winter for the past six years and just recently read Winter Blues by Rosenthal and realized that the 30 min I had stuck to for light therapy probably hadn’t been enough. I now do about an hour right when I wake up, and about an hour later sometime before 2 or 3 PM. Lately my body has been waking up between 4:30 (yikes!) and 5:45, which has not been great for me. I have shifted my bedtime earlier and I fall right asleep, but am tired of waking up so early and not being able to fall back asleep- and, I am okay with bed at 9:30 or 10, but don’t want to sleep earlier because then I miss so much of my evening, but since my body wakes me up so early, I am seriously exhausted by 8 PM. I’m 28 years old, active, and by 8 PM I feel like I’m 90 years old!!! Is there any way to alter my light therapy so that I can sleep in later? Try less or at a different time? Thanks for your help!

You are making a big mistake with self-treatment.  See Dr. Terman’s book, Reset Your Inner Clock, for a detailed explanation of setting light therapy parameters: duration of the session, timing of the session relative to your circadian (“inner”) clock, intensity of the light, sitting distance from the light box screen, and spectral quality (amount of blue in the white color mixture).  In a nutshell, you almost certainly have given yourself a light overdose by doubling the duration of exposure upon wake-up.  If 30 minute sessions were inadequate – which implies persistent, residual symptoms of depression – you might increase exposure duration in a series of small steps (such as 5 minutes), testing each step for three or four days before increasing it further.  A 60 minute exposure at 10,000 lux is virtually the maximum used in clinical practice, most often for patients who have not responded at all to shorter durations.  A major effect of such overdose is a large shift in the circadian clock to an earlier hour, resulting in premature awakening and evening sleepiness – just as you describe.  Adding another hour of light exposure later in the day is almost surely also excessive.  If you are slumping in the afternoon, a relatively short supplementary session – such as 10 or 15 minutes – is sufficient for most people to truncate the slump.

I’d like to try a dawn simulator because I want to get up at 6 a.m., and the sun isn’t up yet (and the alarm is horribly jarring). But I’ve also had symptoms of SAD for a long time, and am considering a light box. Is there any reason not to do both? Is there any way to effectively combine them–i.e., use a dawn simulator hooked up to a light box?

Good question. A paper that came out in the December 2006 American Journal of Psychiatry reports that naturalistic dawn simulation (as described on our website) produces a similar effect to post-awakening bright light therapy for treatment of SAD. The implication is that you probably don’t need to combine the two methods–either one can work on its own. We sometimes combine the two for additional effect when patients (a) are sleeping very late, into the afternoon, and need to adjust their internal clocks earlier by several hours, or (b) awaken successfully with the artificial dawn but feel they need an additional energy burst to jump start the day. You cannot connect a dawn simulation controller direct to a bright light box, because the fluorescent lighting system is incompatible with the dimming circuitry. Thus, if you are using both methods, you will need a separate incandescent bedside lamp with adequate projection toward your bed (as described on our website).

I believe I have SAD as I know my body and mind respond favorably during summer months and I get depressed when we lose daylight hours. I have also always been prone to depression, worse in winter months. Obviously SAD is proof positive of a circadian rhythm disturbance. Because I’ve always been a “night owl,”, I’ve investigated sleep disorders and found out about delayed sleep phase disorder (DSPD). My “body clock” can literally make me turn night and day around if left to my own devices. I was told by my mother that even as a baby she had a hard time getting me to sleep and I’ve always been unnaturally tired in the morning even with a full 8 hours sleep. My question is, would light therapy be useful in my case?

Glad you’re gaining this insight. Delayed sleep phase, difficulty awakening, and depressed mood often come in a “package”, whether seasonally or non-seasonally. Light therapy has been designed and tested for this indication, and we urge you to try it. We can’t be sure from your description, but it sounds like successful treatment may require clinical supervision with dosing adjustment of the light (intensity, exposure duration and time of administration), possibly in combination with other chronotherapy procedures. Thanks for writing.

I have at least some degree of depression on a year-round basis with a worsening in the winter months. In the past, I’ve responded very well to treatment consisting of continuous antidepressant medication and the addition of light therapy in the winter. I’m about to start my light treatment for the winter, however, this year, my symptoms feel a bit different from previous winters: on top of the usual depression, I also feel anxious and edgy. Will my light box help the anxiety too? From reading your site, I’ve seen that some people get agitated as a side-effect of using their light boxes, and although that hasn’t happened to me in the past, I certainly don’t want to feel more tense than I do now. Thanks for any guidance you can provide.

Although SAD is often characterized as a “lethargic” depression, in fact, anxiety symptoms are present in a majority of cases. Your case is more complicated in that previous winters were without such symptoms, and your case is not simple SAD. Light therapy elicits anxiety symptoms only in a small proportion of patients; in most cases, patients find it energizing yet calming (not really a contradiction in terms!). When anxiety symptoms occur as a side effect, this is almost always a sign of “overdose” that is correctible by reducing intensity or exposure duration or scheduling the lights later in the morning. Clinical guidance and monitoring are a sine qua non. Also, keep in mind that although anxiety symptoms are often secondary to depression, an anxiety disorder can be primary, in which case we do not recommend light therapy.

I am a 22-year-old female who has had chronic fatigue syndrome (CFS) for almost two years. During that time, my sleep has been awful. I’ve had difficulty falling asleep, staying asleep, have experienced severe body aches for hours on end, and awoken from 2-4 hours of unrefreshing sleep feeling worse than before. I dreaded bedtime and began taking melatonin supplements at night; I noticed immediate results. I can now generally get 6-8 hours of somewhat refreshing sleep at night, although the beginning and ending times are extremely variable (10:15pm – 2:00am start, 4:00am-9:30am end). I have never had any reason to suspect SAD before, but have noticed since the onset of CFS symptoms that I feel significantly worse on cloudy days. I am much more fatigued than other days, feel rather drab, cannot concentrate as well, and combat feelings of disappointment and sadness at times. I have noticed myself subconsciously staying near brightly lit places. I’m wondering if light therapy might be useful. I don’t want to take any more pills than I already am and don’t want to waste money for something unbeneficial. What’s your opinion?

We bet you have not seen CET President Michael Terman’s article with CFS expert Susan Levine: “Chronic fatigue syndrome and seasonal affective disorder: comorbidity, overlap, and implications for treatment.,” American Journal of Medicine 1998;105:115S-124S. It turns out that the hallmark symptoms of SAD occur just as frequently in patients with CFS. In a series of case studies, light therapy produced marked improvement. Patients with SAD also often slump during a string of dark, rainy summer days–and they find their light boxes as useful then as in winter. More importantly, we think, patients with CFS spend an inordinate amount of time indoors and in bed, creating an artificially darkened environment.

As we have learned from recent clinical trials of patients with non-seasonal depression, light therapy can work year-round. Indeed, long winter nights are just one of many ways we come to spend excessive time in the dark. Our advice is to follow the guidelines we offer on our website for light box selection and scheduling (take the Morningness-Eveningness Questionnaire). It would be best to do this under monitoring by your clinician, since if you show gains it may be possible to taper your medication regimen. If your clinician is inexperienced with or skeptical about lights, refer him or her to the August 2005 issue of the journal CNS Spectrums for a comprehensive review. One word about melatonin use inconjunction with light therapy: never employ the latter in the hours after taking melatonin, because it is a photosensitizer. As a general rule, schedule evening melatonin at low dose, 12 hours before you use the lights.

Living in upper New York State with low winter daylight, I wonder if flooding the house with overhead bright light to simulate overhead sunshine would be of any benefit. I mean to make it as bright as a sunny day outside, inside the entire house. I’m sure our electric bill would rise, but leaving our home would be an extreme solution. I have noticed a pattern of winter anxiety in my daughter for four years now (she’s 10) and I know I can deal with my SAD, but if I can change it for her, I want to. We have taken extended winter vacations south and everyone sees benefits. Would a move be better in the long run? Thanks for supplying this forum. There are many interesting questions and answers. It is very informative

Your proposal, we have to say, is well-intentioned but impractical as well as unnecessary. Instrumenting overhead lighting at full daylight intensity has been done only in a few research laboratories, at great expense, including for dedicated high-power air conditioning to expel the high heat load. It makes more sense to follow established winter light therapy regimens, which focus illumination on the final period of sleep or the period immediately following wake-up. Almost always, that is sufficient to allay winter symptoms.

We suggest completing our Morningness-Eveningness Questionnaire, and scheduling restricted light exposure accordingly. Kids may find dawn simulation most acceptable, since it is automated in the bedroom and requires no daytime behavioral compliance. If your family is contemplating a move south, before making the commitment we recommend testing one winter at your selected destination to make sure it does the trick. Some people are disappointed to find that winter depression can follow them down south, even though days are relatively longer than in the north

This may sound strange: Is there an opposite disorder to SAD where sunlight actually depresses you? I’ve struggled with sunlight for about 10 years, but have had no skin reaction, other than a melanoma a couple of years ago. I really have a hard time getting through sunny days in a normal manner. It is amazing how wonderful my days are when it is overcast outside.

This is an unusual report, but there are some possible explanations. Some people experience “photophobia”–with very disruptive reactions to bright light exposure, which may be related to hypersensitivity of the retina of the eye, psychological factors, or both. If you use a photosensitizing medication, that may be responsible. There have been scattered reports of people becoming very sleepy during and after bright light exposure; it is not clear whether this is due to the time of day of light exposure. Possibly, your reaction to outdoor sunlight is triggered by the strong blue component of white light. If so, you may benefit by using blue-blocking wrap-around glasses, such as Model 58 from http://noirmedical.com/uv_yellow.htm#Light. Finally, you may be suffering from summer depression, which is more plausibly related to high heat and humidity than bright light.

My daughter has been diagnosed with SAD and has purchased a light box which is helping her with waking and sleeping. She is 22 years old. Since she was about 10 years old, she has slept in the basement in a room without any windows. She has always had great difficulty waking up in the morning and going to sleep at night. Could sleeping in a room without natural light have had an impact on her sleep cycle?

Amen and amen. Our bodies have a physiological NEED to receive natural (or appropriate artificial) light early in the morning in order to stay in sync with external day and night. Dark basement conditions provide an environment conducive to developing and maintaining delayed sleep phase disorder (DSPD). This is often correctible with light therapy. We have long wanted to prepare a cet.org website section with a detailed discussion of DSPD and guidelines for how to rectify it. However, this will require additional visitor support. Please remember, contributions to CET–see the “Donate” page at www.cet.org–are tax-deductible under IRS 501(c)(3).

The CET Store offers two different light boxes, one of which uses a color temperature of 6500 Kelvin and the other, 4000 Kelvin. Also, one produces 7500 lux light intensity, and the other, 10,000 lux. Do these two units have different effectiveness, results, and purposes? How do I decide which would be better for me?

Before we answer, please note that last year’s (2003) model of the 10,000 lux device used lamps with 3000 Kelvin color temperature, which is perceptually a bit pinkish relative to the current 4000 Kelvin. Higher Kelvin does not necessarily translate into higher light dose, however. Both of our recommended units have been demonstrated to have antidepressant efficacy, although formal clinical trials for SAD have yet to be performed for the 7500 lux model.

The 7500 lux device was originally designed for enhanced work station lighting, to be flexibly used throughout the day at either low, medium or full intensity. This device has now also been positively evaluated at full intensity in patients with non-seasonal antepartum or bipolar depression, and there is no reason to think that it would not also work for SAD.

With lower maximum light output, some people will find that they need to increase exposure duration beyond the 30-minute average used with the 10,000 lux device. In antepartum depression studies, for example, patients used the 7500 lux device for 45-75 minutes; in a past SAD trial with another device providing about 7500 lux, everyone was treated for 90 minutes per day.

Because the manufacturers of these devices have chosen to use different color temperatures, however, it is impossible strictly to compare lux levels. All other things being equal, 6500 Kelvin appears whiter and brighter, while 4000 Kelvin appears softer. Both contain wavelengths that are active in the therapeutic range. We have named the 10,000 lux device a “clinical” unit, mainly because it has been extensively formally tested in clinical trials of SAD and chronic depression.