A controlled trial of the Litebook
light-emitting diode (LED) light therapy device for treatment of
Seasonal Affective Disorder (SAD)
Paul H Desan1
, Andrea J Weinstein1
, Erin E Michalak2, Edwin M Tam2, Ybe Meesters3, Martine J Ruiter3, Edward Horn4, John Telner4, Hani Iskandar5, Diane B Boivin5 and Raymond W Lam2
1Department of Psychiatry, Yale University, PO Box 208068, New Haven, CT 06520-8068, USA
2Mood Disorders Centre, Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
3University Medical Center Groningen, Groningen, The Netherlands
4Royal Ottawa Mental HealthCentre, Ottawa, Ontario, Canada
5Centre for Study and Treatment of Circadian Rhythms, Douglas Hospital Research Centre, Montreal, P. Quebec, Canada
BMC Psychiatry 2007,
7:38doi:10.1186/1471-244X-7-38. [Open Access article]
Abstract
Background
Recent research has emphasized that the human circadian rhythm
system is differentially sensitive to short wavelength light. Light
treatment devices using efficient light-emitting diodes (LEDs) whose
output is relatively concentrated in short wavelengths may enable a
more convenient effective therapy for Seasonal Affective Disorder (SAD).
Methods
The efficacy of a LED light therapy device in the treatment of SAD
was tested in a randomized, double-blind, placebo-controlled,
multi-center trial. Participants aged 18 to 65 with SAD (DSM-IV major
depression with seasonal pattern) were seen at Baseline and
Randomization visits separated by 1 week, and after 1, 2, 3 and 4 weeks
of treatment. Hamilton Depression Rating Scale scores (SIGH-SAD) were
obtained at each visit. Participants with SIGH-SAD of 20 or greater at
Baseline and Randomization visits were randomized to active or control
treatment: exposure to the Litebook LED treatment device (The Litebook
Company Ltd., Alberta, Canada) which delivers 1,350 lux white light
(with spectral emission peaks at 464 nm and 564 nm) at a distance of 20
inches or to an inactivated negative ion generator at a distance of 20
inches, for 30 minutes a day upon awakening and prior to 8 A.M.
Results
Of the 26 participants randomized, 23 completed the trial. Mean
group SIGH-SAD scores did not differ significantly at randomization. At
trial end, the proportions of participants in remission (SIGH-SAD less
than 9) were significantly greater (Fisher's exact test), and SIGH-SAD
scores, as percent individual score at randomization, were
significantly lower (t-test), with active treatment than with control,
both in an intent-to-treat analysis and an observed cases analysis. A
longitudinal repeated measures ANOVA analysis of SIGH-SAD scores also
indicated a significant interaction of time and treatment, showing
superiority of the Litebook over the placebo condition.
Conclusion
The results of this pilot study support the hypothesis that light therapy with the Litebook is an effective treatment for SAD.
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