Am J Psychiatry 1995; 152:1197-1202
Copyright © 1995 by American Psychiatric Association
The phototherapy light visor: more to it than meets the eye
MH Teicher, CA Glod, DA Oren, PJ Schwartz, C Luetke, C Brown and NE Rosenthal
Department of Psychiatry, Harvard Medical School, Boston, USA.
OBJECTIVE: The purpose of the study was to ascertain whether phototherapy
light visors provide an effective treatment for seasonal affective
disorder. Previous studies have demonstrated a moderate response rate but
have failed to find any difference in efficacy between light intensities.
METHOD: Subjects were randomly assigned to receive, over a 2-week treatment
period, 30 minutes of morning phototherapy with a light visor that emitted
either a dim (30-lux) red light or a bright (600-lux) white light. Raters
were blind to treatment, and patients were unaware of the alternatives.
Response was assessed by using the structured 21-item Hamilton Depression
Rating Scale, with an eight-item addendum for atypical depressive symptoms.
Fifty-seven patients were enrolled across two sites. RESULTS: Patients
assigned to the different visors had similar baseline depression scores and
similar expectations of outcome. Hamilton depression scale scores declined
by 34.6% for subjects given bright white light and by 40.9% for subjects
given dim red light. Scores for atypical depressive symptoms fell by 44.1%
for patients assigned the bright white light visors and by 49.0% for
patients assigned the dim red light visors. Altogether, 39.3% of the
patients who received red light and 41.4% of the patients who received
bright white light showed a full clinical response. CONCLUSIONS: There were
no significant differences in therapeutic response between patients who
were treated with red or white light. The results of this study suggest
that the phototherapy light visor may function as an elaborate placebo.
Alternative explanations, however, are considered.
