Mood Relief: Portable Light Therapy

Light therapy has been shown to be an effective treatment for people suffering from mood disorders, including depression, seasonal affective disorder (SAD) and bipolar disorder. Where light therapy equipment was once cumbersome and difficult to transport, modern light therapy involves portable units as small as a hand which can be easily moved, making it easier to go about your daily tasks, such as reading, sleeping or writing a letter, while being treated. If you suffer from a mood disorder, ask your doctor about the benefits of portable light therapy.

How it Works

• Portable light therapy units treat mood disorders by delivering more light to the retina. The increase of light helps to alter the body's natural circadian rhythms and decrease the production of melatonin--the hormone which causes the body to feel sleepy. The excess light also causes the brain to release more glucocorticoids into the bloodstream; these hormones speed up the body's metabolism, reduce stress and inflammation and boost immunity.

Instructions for Use

• Portable light therapy units are traditionally used during the early morning hours. You may set the box a few inches above your bed, programmed to turn on an hour or two before you wake up, or you may place it above your kitchen table while you eat breakfast. The light box should be several inches above your face, pointing downward so that the bottom part of your retina receives as much light as possible. This method reduces the chance of damaging the retina by looking directly into the light box, and it also provides the retina with a simulation of sunlight. The unit should be used for approximately half an hour each morning and no longer than an hour a day, as the light that emanates from the box is much brighter than typical sunlight exposure.

Precautions

• People who have a photosensitivity or phototoxicity condition of the skin or eyes should not use portable light therapy boxes. Patients taking certain drugs that make the skin more vulnerable to the effects of sunlight should also avoid portable light therapy treatments until a few days after the drugs are no longer in their systems. Never apply photosensitizing creams or lotions before using a portable light therapy device, as this could lead to skin damage. If you suffer from bipolar disorder, consult your doctor before beginning any light therapy treatment, as you will need to be carefully monitored by a trained clinician for signs of mania while you are being treated. Light therapy, like other types of antidepressant therapies, can induce manic states in people with bipolar disorder, so you should weigh the risks versus benefits of light therapy before undergoing treatment.

Types of Light

• Portable light therapy units can either deliver white (full-spectrum) light, blue light or green light. While full-spectrum lights are stronger than blue or green, they may not filter out enough of the ultraviolet (UV)rays to be safe with regular use. Blue light units filter the damaging UV rays and are the most popular types of light therapy units sold today. Green light units filter more rays than blue light units but may not be as effective as white or blue light in treating mood disorders.

Risks

• The risks of photo light therapy have not been studied over the long term. There is a slight risk that people with bipolar disorder may develop full-blown manic episodes while undergoing light therapy, but this risk can be managed with the supervision of a trained clinician during treatment. Other risks include macular degeneration in people who look directly into the light source over a long period of time, phototoxicity or photosensitivity with long-term use in people who have a predisposition to these conditions and possible skin damage with long-term use of the full-spectrum white light therapy boxes.

Possible Side Effects

• Possible side effects of light therapy include nausea, irritability, vomiting, headache, difficulty sleeping, dry mouth, mania (in manic-depressives) and eye strain. Most side effects are mild when they occur and may go away after the patient has adjusted to the levels of bright light. Patients are counseled to change the time of day when they undergo treatment or take breaks during longer treatments to avoid potential side effects.