Light therapy is a powerful and natural solution for a wide range of conditions including circadian rhythm disorders, jet lag, and depression.
When we hear the words “light therapy” most people probably think of SAD or Seasonal Affective Disorder. It is true that light therapy is most often prescribed for this disorder, but, as it turns out, it may be useful for much more.
As with any kind of treatment or therapy, this is something best done under the supervision of a doctor or health care professional, and there are certain conditions in which light therapy would be adverse.
What Is Light Therapy?
Let’s take a look at what light therapy is. A quick Google search will give you a barrage of information, and it can be difficult to sort through what is relevant. To ensure accurate information that isn’t skewed in favor of what a website is selling, it is best to go with reputable companies and well-maintained websites.
According to the Mayo Clinic website, light therapy “is a way to treat the seasonal affective disorder (SAD) and certain other conditions by exposure to artificial light.” But not just any artificial light. If that was all that was needed, no one would need light therapy because exposure happens merely by going about life.
Light therapy may be popular now, but it is not a new idea. Once called heliotherapy, it is known to have been used by Hippocrates in ancient Greece. In the 1800’s heliotherapy was a common therapy for tuberculosis and lupus vulgaris, which is a skin disorder caused by the same bacteria that causes tuberculosis. (It should be noted that this is very different from systemic lupus erythematosus, which is what the term lupus normally brings to mind. It’s another disease entirely.)
It was during this period that mechanical means were invented to provide heliotherapy when the sun was not available. The most well-known of these is probably the Finsen Lamp, an ultraviolet lamp developed by physician Niels Ryberg Finsen. Dr. Finsen won a Nobel prize for his invention in 1903.
Modern light therapy usually involves what is called a lightbox. A lightbox is a device that emits a very bright light of a certain wavelength. Frequency and intensity are important to reach a therapeutic level. Intensity is measured in units called Lux.
For comparison: according to psychoeducation.org: bright moonlight is 1 lux, a candle is 10-15 lux, office lighting is 300-500 lux, etc. The scale increases up to bright sunlight, which is 20,000-100,000 lux.
There seems to be a consensus among various studies that therapeutic levels are 10,000 lux for 20-30 minutes.
How Does Light Therapy Work?
When used to alleviate symptoms of ‘seasonal affective disorder‘ and circadian rhythm disorders, it seems to work on receptors located in the retina of the eye. As explained by Dr. Phelps in “Light Therapies For Depression”, when using a lightbox the device must be positioned so the light hits the receptors at the bottom of the retina.
These receptors are what communicate to the brain that it needs to prepare the body for the activities of the day. What does this have to do with mood? Dr. Phelps further explains, “We think that some people are built to slow down in the winter, something akin to hibernation. Think of a hibernating bear; sleepy, slow, hungry for carbohydrates, unhappy if awakened, grouchy: grrr.
Those symptoms are pretty close to the experience of “winter blues” for some people.” This is a perfect analogy to describe something that can have an effect on our sleep and our mood. It becomes a self-perpetuating cycle.
As it gets dark earlier in the evening’s someone might begin to feel down. A natural reaction to feeling down is to withdraw, and withdrawal usually brings less activity, heavier eating, feeling sluggish, feeling tired; that leads to even less exposure to light, which affects not only the hormones such as melatonin that regulate sleep but also the body’s ability to manufacture vitamin D on its own.
A deficiency in vitamin D can cause or exacerbate many health issues, such as osteoporosis (vitamin D helps the bones absorb calcium.), as well as “certain cancers, cardiovascular disease, autoimmune diseases, infections, inflammatory bowel disease, psychological disorders, cognitive disorders, obesity, and or mortality.”
Who Should Explore Light Therapy Treatments?
As stated earlier, light therapy (also sometimes called phototherapy or bright light therapy) is most often associated with seasonal affective disorder and other forms of major depression.
SAD is a form of major depressive disorder experienced by many people during the fall and winter months due, it is thought, to lowered exposure to sunlight. It makes sense, therefore, that light therapy would alleviate some of the symptoms of this common disorder. Think of the hibernating bear analogy of Dr. Phelps again.
Light therapy may also be used in instances when an alternative to antidepressants is needed, such as when a woman is pregnant or breastfeeding. Many women are afraid of antidepressants during pregnancy or breastfeeding and feel more comfortable using alternative methods, such as light therapy. It must be stressed, though, that this decision should be made in conjunction with and under the supervision of a physician or healthcare professional.
Occasionally a patient needs to be on a lower dose of antidepressants. For instance, a patient who is not tolerating antidepressants well or who is having liver or kidney issues might need to go on a lower dose of antidepressant, and light therapy may facilitate that.
There are also a variety of circadian rhythm disorders in which light therapy may be useful as treatment, either alone or in conjunction with other therapies.
Who Should Avoid Light Therapy Treatments?
There are certain things that would make light therapy a bad idea. People who suffer from Bipolar Disorder are not likely to be helped with this form of treatment, and in some cases, it may actually exacerbate symptoms. Because of the brain chemistry involved in Bipolar Disorder, light therapy can bring on manic episodes. Since it increases the amount of serotonin, think of light as an antidepressant.
Bipolar disorder is not treated with antidepressants but rather with mood stabilizers, a type of psychotropic medication that helps regulate the highs and lows associated with Bipolar Disorder.
Patients who have a history of eye photosensitivity or have conditions that may make them more sensitive to light will not want to consider this treatment.
Eye conditions such as glaucoma, cataracts, retinal detachment, or diabetic retinopathy would find this treatment adverse People with macular degeneration, either in themselves or in family history should not use light therapy.
There are also certain medications and supplements which would cause increased sensitivity to light. Antibiotics, anti-inflammatory medications, antihistamines, lithium, melatonin, and the herbal supplement St. John’s Wort are just a few examples of things taken internally that would affect an individual’s ability to withstand strong light.
Other medications that may that may make light therapy difficult include: phenothiazines (a form of antipsychotic), some cardiac anti-arrhythmic medications, treatments for psoriasis, anti-malarial drugs, tetracycline, diuretics, sulfa drugs, and tricyclic antidepressants. All of these are known to increase sensitivity to light.
It is also important to remember that some skin creams, especially anti-aging creams that contain medications and vitamins such as retinol, can cause reactions to light. Essentially, it is best to check for contraindications before using this therapy.
Many other genetic and medical conditions would make light therapy a poor choice. Porphyria is the name given a group of genetic disorders characterized by abnormalities in the production of heme, a molecule most prominent in our blood, bone marrow, and liver. There are two main types of porphyria.
One affects the skin, causing it to redden, burn, and blister in the sun; the other attacks the nervous system. Lupus (systemic lupus erythematosus) is another disease by which sufferers are prone to light sensitivity. In addition, those with such conditions as actinic dermatitis (severe sun damage), solar urticaria (your skin hurts when in the sun) would want to avoid light therapy.
What Problems Does Light Therapy Work On?
We know that light therapy is effective for seasonal affective disorder. What else does it work on?
Circadian rhythm disorder is an umbrella term for sleep disorders that stem from a disrupted internal body clock. These are divided into two categories: intrinsic (organic or biologically based) and extrinsic (circumstantial, ie. factors that we can control.) So how does light therapy come into play in correcting these issues?
According to Kevin Phillips of the Alaska Sleep Clinic, what should happen is that as morning arrives, our body temperature and blood pressure rise and melatonin levels decrease, which is what helps us wake up. If our biological clock, the circadian rhythm, is disrupted or offset, this either does not happen at normal levels or does not happen at acceptable times.
Beyond the two main categories, the following are the six types of circadian rhythm disorders.
Advanced Sleep Phase Syndrome occurs when a person goes to bed earlier in the day than most people. These are the people who are so tired they are in bed two hours or more before most people.
The trade-off is they are often waking much earlier than necessary, resulting in being exhausted much earlier in the day than those with a normal sleep-wake cycle.
- Delayed Sleep Phase Syndrome occurs when someone doesn’t get sleepy until much later than most people. However, since the person suffering from this usually needs the same amount of sleep as others in their age group, this makes waking up in the mornings much more difficult. These are the people who hit the snooze button ten times before getting up. They essentially aren’t functionally awake until later in the morning or mid-day.
- Irregular Sleep-Wake Syndrome occurs when a person doesn’t have a typical pattern of sleep. Their sleep instead comes in the form of naps. With no regular schedule, the body cannot regulate itself.
- Non-24hr Sleep-Wake Syndrome occurs when a person has a cycle that is somewhat longer than 24hrs. Think of it as a clock running a little slow, and every day it loses a little bit of time. The brain of a person with this disorder would signal time for slightly later each day, and so the sleep cycle would be shifting every few days.
- Shift Work Sleep Disorder is just what it sounds like: a circadian rhythm disorder that affects people who alternate shifts from week to week, or even day to day within the same week. This can seriously disrupt an individual’s internal clock, making sleep seem like an unattainable goal.
- Jet lag also falls within the realm of circadian rhythm sleep disorders, although this is one that is usually temporary and easily fixed. This would be a more serious problem in people who travel frequently in and out of different time zones, and in cases like this light therapy would likely be useful.
Regardless of whether the cause is intrinsic or extrinsic, the effect on mood and physical health can be devastating.
According to the Alaska Sleep Clinic, whether “a person’s circadian rhythm is disrupted by external forces or circumstances (demands from jobs, schools, or travel) or their own biological clock is offset from the majority of society…people begin to develop circadian rhythm sleep disorders, and if left unchecked can lead to issues ranging from exhaustion and confusion to medical problems such as obesity, diabetes, depression, and dementia.”
The symptoms may seem mild at first, but over time they can have serious consequences for mental and physical health.
What Are Your Light Therapy Options?
Things have advanced significantly since the days of the Finsen Lamp. There is a wide variety available to choose from, in a variety of price points. No prescription is needed to obtain one, although it must be stressed that light therapy should be supervised and monitored by a physician or healthcare practitioner.
The most important thing to remember is the reason the light is needed. Lights intended to treat the seasonal affective disorder and other forms of depression emit full spectrum light. Manufacturers also try to filter out harmful UVA and UVB rays, which have been connected to skin cancer.
This means that tanning beds are NOT a suitable alternative, as they rely on UV rays and can cause damage to skin and eyes. Devices intended to treat skin disorders, such as psoriasis and vitiligo, also rely on UVA and UVB rays and would not be suitable for mood disorder treatments.
Lightboxes meant for treatment of mood disorders and circadian rhythm disorders can be found in many markets, both online and brick-and-mortar. There are several manufacturers, and sizes range anywhere from a lightbox approximately the size of a large mobile phone to the large ones used in actual research studies (Carex). There are also units that only put out blue light as opposed to full spectrum white light.
The larger research-quality unit is more expensive, but even the cost of that has dropped in recent years. In fact, the Carex website itself has units in the range of $200, and some of the smaller units from this manufacturer range $135.
According to Phelps, some of the other brands that you can find may be less expensive, but they are also cheaply made and possibly not as effective.
There is another alternative if an individual isn’t quite sure about which product to invest in. A product called a ‘Dawn Simulator’ is a device that, beginning about an hour before a person is set to wake up, gradually increases the light in the room as it nears time to awaken.
This is supposed to trick your brain and break it out of the “hibernation” mode it seems to want to go into.
Fortunately, this is one option where more expensive models don’t seem to provide any additional benefit over the cheaper ones, as far as mood and circadian rhythm goes. This may also be an option for those with Bipolar Disorder, as the Dawn Simulator has not been observed to trigger the mania or hypermania episodes that a light box may.
Getting The Most Benefit From Light Therapy
How do you ensure you’re getting the most benefit from your light therapy treatments? The cardinal rule, which cannot be stressed enough, is to partner with a physician or other healthcare provider. While light therapy should be mostly free of side effects, mood disorders are complex and need careful medical monitoring.
Note: No treatment or therapy should be started or stopped without consulting your healthcare team. Self-monitoring is important as well. If something isn’t helping, or isn’t helping as much as it should, it is important to tell your healthcare professional. Adjustments may need to be made, or something may need to be added to the light therapy.
Second, learn how to use the device properly. There is a therapeutic strength of light (at least 10,000 lux), a therapeutic distance, and a therapeutic length of time for treatment. Any one of these variables being insufficient is enough to change the outcome of the therapy.
The third thing to remember is consistency. No therapy, whether natural or pharmaceutical in nature, is going to work well without an effort to be consistent. Light therapy should ideally be done every day in order to get the most benefits from it.