Seasonal affective disorder (SAD), a syndrome characterized by
recurrent depressions that occur annually at the same time each
year, affects an estimated 4 percent to 6 percent of the general
population. It's the prevalence of SAD and other depressive
disorders that have pioneered the discovery of an effective treatment
method: Light therapy.
A report of the study, based on a meta-analysis, also found the
effects of light therapy, or phototherapy, are comparable to those
found in many clinical studies of antidepressant drug therapy for
mood disorders. (The use of bright artificial light to treat SAD
was first described in the Archives
of General Psychiatry in 1984.)
Meta-Analysis Results
The studies used in the meta-analysis were grouped into four categories
that were limited to adults, ages 18-65, who met a certain mood
disorder diagnosis:
- Bright light for SAD
- Bright light for non-seasonal depression
- Dawn simulation for SAD
- Bright light as an adjunct therapy (combined with conventional
antidepressants for non-seasonal affective disorder)
Dawn simulation is a technique that attempts to replicate an earlier
dawn through exposure to artificial light. This treatment strives
to simulate the increased intensity of sunlight of a naturally occurring
summer sunrise. According to the report, the meta-analysis demonstrated
statistically significant treatment effects for SAD, dawn simulation
for SAD and bright light treatment of non-seasonal depression.
American
Journal of Psychiatry, April 2005, Volume 162, Number 4: 656-662
Medical
News Today April 9, 2005
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