Healing Depression with Light Therapy

Think about the dark dungeons of despair, the heart of darkness, the gloominess of a funereal mood.  This language tells us what people have always known.  Sadness rules where it is dark.  Now think about a person who has “Seen the Light”.  Think about brilliance.  Think about how we describe the  scintillating joy of love by singing, “You are my sunshine.”  We know that light makes us happier.  Now consider most plants.  They thrive in sunshine and easily wilt when brought indoors.  People, just like plants, were designed to be outside.  It is part of what makes us human.

Perhaps somewhere back in evolution, our ancestors roamed the forests then they moved out more into equatorial fields and savannahs, became able to run further, and started looking about further for food.  It was always bright near the equator where they lived. Much of the time, there was hardly even partial shade.  It makes sense that our modern human ancestors became intelligent in places which were indeed very sunny.  It is for such a life that our bodies are adapted.

As we became more civilized, about the time that recorded history began, our ancestors were still outdoors people.  The men were outdoors hunting, fishing, farming, and fighting.  The women were outdoors farming also, when they were not gathering food, grinding grains, weaving, cooking, or doing other things done mostly outside to take advantage of the sunlight.  In China, India and many parts of the developing world, people still spend a considerable amount of time outdoors.

As society evolved, we built dwellings and developed electricity thus beginning the process of moving much of our lives indoors.  In fact, it has now become very common for most of us to spend the majority of our days indoors.  A research study revealed that even in the beautiful city of San Diego, a year round sunny and temperate climate, the average individual spends only about 1 hour per day outdoors.

We know now that many people who have limited amounts of sunshine exposure are prone to developing SAD, seasonal affective disorder.  This is a type of depression that can range from mild symptoms to full-blown classic symptoms of a major mood disorder.  People may report feeling irritable, sad, lonely or just plain tired and fatigued.  They report difficulty in falling asleep as well as difficulty in waking up.

Many people with seasonal affective disorder experience increased carbohydrate craving such as eating sweets, and they sometimes gain weight and need larger clothing in the winter.  Other people however may report the loss of appetite and even lose weight.  Some people with SAD feel withdrawn and want to curl up like a hibernating bear while they may have fewer symptoms of sadness and guilt than in other forms of major depression.

Classically, SAD has been described as a winter malady but there is some evidence that in parts of the country with intense heat during summer months, indoor lifestyles have induced SAD in some individuals as well.

There is good news for depressed people!  You can often make yourself happier simply by lighting up your life!  With some advice from your doctor, you can relieve depressive symptoms by getting more bright light.  Just as darkness makes us sad, bright light tends to restore us to a normal level of cheer.  This simple and very helpful principle helps us treat depression naturally.

The most important aspect of treatment lighting is that it be very bright.  So far as we know, sunlight and artificial lighting work equally well.  However, in various climates, environments, and social situations, using sunlight may be impractical, so most people will need to buy, rent, or borrow special artificial lighting.

The most common device used for bright light therapy is a fluorescent light box which produces a light intensity of 2,500 to 10,000 lux at a comfortable distance (1-2′).  Full-spectrum light is not necessary since intensity is most important, but a balanced-spectrum light minus UV-B emissions is considered ideal. Fewer headaches and eyestrain are associated with using balanced spectrum light. Most light boxes cost from $250 to $525.  There are individual differences, but a 1/2 hour treatment at 10,000 lux or a 1 hour session at 5,000 lux once a day is the average. Most are comfortable with the 10,000 lux intensity level, and choose a unit that produces 10,000 lux at a usable and comfortable 13-16″ distance from the light box.

The most successful treatments for SAD involve identifying how the change in daylight shifts an individual’s daily circadian rhythms, especially in their sleep cycle.  Most people with SAD symptoms show changes in their sleep/wake patterns and melatonin levels. Bright light is known to be a powerful regulator of melatonin as well as the sleep/wake cycle.   S.A.D. and “Winter Blues” sufferers tend to show two common patterns in their sleep phase disruptions: Delayed or Advanced.

About 80% of people show the delayed pattern of sleep disruption.  For these individuals, melatonin production and onset of sleep begins later at night, and continues into the normal morning waking hours. These people have trouble waking up in the morning, and often feel sluggish for hours after awakening, even if they have slept longer than usual. Phototherapy sessions appear to be most effective for this group if delivered between 6-8 a.m. Some of these people also experience a time during late afternoon or early evening when they become tired and sleep again. Of those in the phase-delayed group about 50% have this tired time. Then late evening arrives and their energy levels increase, which makes going to bed at a normal time difficult. This may subsequently result in poor sleep quality. For those individuals, an optional second session of 5 to10 minutes at 10,000 lux between 3-7 p.m. helps change this pattern and often improves overall sleep quality. This additional light may, however, cause some users difficulty going to sleep due to the energizing effect of the second light session.

About 20% of people with SAD  feel best in the morning, then around noon their energy levels steadily decline. Often they retire for the night hours earlier than normal. Their 30 minute session at 10,000 lux is usually placed from 3-7 p.m., depending on when the urge to sleep occurs and how late the light may be used without keeping them awake. Timing is more individual for this group, and may require trial and error for optimum effect. Short, periodic sessions throughout the afternoon at high intensity, or long exposure at a lower intensity may also be considered. A second session in the morning is often not beneficial for this group.

Regular daily usage at the same time each day is best until symptoms disappear. After that period an individual may be able to cut session time or split a half-hour AM session into 15 minutes a.m. and p.m. Once established, most people can skip a couple of days without ill-effects, but by the third day without light therapy most individuals will see symptoms return. Light therapy sessions should begin at the time of the year before symptoms become obvious or distressing, and most patients will discontinue use in the spring when they receive enough natural light. The times when usage is necessary can be greatly affected by the amount of sunlight or cloudy rainy weather.

It is possible to overuse a light box.  Irritability, agitation and initial eyestrain for 1-3 days appear to be the main side effects. Some drugs make patients photosensitive, as can contact lenses, and those patients may need to be conservative when starting light therapy. People on antidepressants can often reduce their dosage, with their doctors consent, once light therapy works. For most folks, light therapy is the most natural and safe treatment for SAD, as well as the most cost-effective.

Exposure to bright light from a light therapy box is thought to alter your circadian rhythms and suppress your body’s natural release of melatonin. Together, these cause biochemical changes in your brain that help reduce or control symptoms of seasonal affective disorder and several other conditions as well.

Given the effectiveness of treatments for SAD it would be a shame for anyone not to seek help. It is true that SAD is often correctly self-diagnosed and anyone can purchase light devices, but other illness factors may be at play, and seeking the guidance of a qualified medical practitioner in both the diagnosis and treatment of SAD is the wisest thing to do.  (Usage patterns outlined herein represent those most typically given by current clinical practices. They are not intended to encourage self-prescription or to contradict an individual’s prescribed therapy.)