Day Light Treatment Benefits

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SAD - Seasonal Affective Disorder:

SAD - or Seasonal Affective Disorder is a full-blown, debilitating, mood disorder, but it is predictable for half the year, at the same time of the year. Experts suggest that as many as 10 million North Americans experience SAD.

If you start feeling lethargic during the fall, have trouble waking up and getting out of bed, start wanting heavy or carb-rich foods, it is a sign that winter doldrums may be setting in. The mood disorder itself usually sets in weeks later - with chronic low mood, inability to do work, loss of pleasure in usual activities, etc. - and is worst in January and February. Usually, everything is fine again by early May.

Anyone can experience SAD cycles, whether or not they occur every year ("like clockwork") or in most years. Women of childbearing age seem most vulnerable, but it can occur from childhood through old age, and men can be just as strongly affected as women.

Bright light therapy is simple to administer, and very effective for most SAD sufferers if they use a well-designed light box on a regular daily schedule. Like drugs, light can be "dosed" by changing the intensity level, the exposure duration and/or the time of day that it is used. The recommended starting dose is 10,000 lux for 30 minutes in the morning. Dosage is then increased or decreased from there to meet individual needs.

A large study of SAD patients undergoing light therapy, published in the prestigious Archives of General Psychiatry, found major clinical improvement in about 80% of cases when the light was scheduled at an optimum early hour. If the light was scheduled later, the response rate dropped to about 40%. For more details about the optimum earlier hour, take the Automated Morningness-Eveningness Questionnaire in the Self Assessment section of this website.

If symptoms are only partially improved after seeking your best lighting dose, it may be helpful to add an antidepressant drug. If symptoms do not improve at all, stop light therapy treatment; drugs provide a potential alternative. Many people are already using drugs when they start light therapy. In such cases, if symptoms quickly and markedly improve, it may be possible to reduce drug dose or eliminate drugs altogether.