THERE IS MORE TO IT THAN MEETS THE EYE.
- Department of Psychiatry, Harvard Medical School and Clinical
Chronobiology Laboratory, McLean Hospital, 115 Mill St., Belmont MA 02178:
Martin H. Teicher, M.D., Ph.D., Carol A. Glod, R.N., M.S.C.S.
- Clinical Psychobiology Branch, National Institute of Mental Health, Building 10, Room 3N228, 9000, Rockville Pike, Bethesda, MD 20892: Dan A. Oren, M.D., Chris Luetke, Paul Schwartz, M.D., Charlotte Brown, M.A. and Norman E Rosenthal, M.D.
Previous research evaluating the efficacy of the light visors in the treatment of Seasonal Affective Disorder have produced unexpected results. Rosenthal et al (1990), compared a 6000 lux and a 400 lux visor in a three center study involving 55 subjects, and found that both visors produced equivalent results. Last year in a five center study with 105 patients, visors of 60, 600, and 3500 lux were compared (Joffe et al., 1991). Again, confounding expectations, all three intensities proved essentially equivalent. Such unanticipated findings suggest two possible interpretations: (1)the light visor is nothing more than an elaborate placebo, or (2) that the visor produces a phototherapy response at stimulus intensities previously believed to be ineffective. In the present study we sought to resolve this problem by COMPARING a 600 lux white visor to a 30 lux RED visor, as previous research has shown that dim red light serves as a believable, but ineffective, placebo.
METHOD AND PROCEDURES:
DESIGN: A blind random comparison study was conducted. Subjects received 2 wks of baseline ratings, 2 wks of visor treatment,and 1 wk of withdrawal. To minimize confounding effects of envirormental light, dark wrap-around sunglasses were worn whenever subjects went out in daylight. Based on our initial power analyses, a minimal total sample size of 40 patients was required. Our final sample size has been estimated at 56. Data are currently available on 49.
SUBJECTS: Adult patients of either sex were recruited for study by clinical referral or newspaper ad. They were studied at McLean Hospital or N.I.M.H., and were evaluated by a clinician experienced in the diagnosis and treatment of SAD. Each subject received a structured clinical interview (SCID), and detailed assessment of their seasonal pattern, and fulfilled Rosenthal-NIMH criteria for SAD, and DSM-IIIR criteria for seasonal pattern. Medicated subjects were included only if they had been on stable medication doses for at least the last month, and agreed to remain on exactly the same regimen during their period of participation.
TREATMENT: Each subject received 30 min AM phototherapy using Bio-Brite Light Visor (research model), which contains 2 incandescent bulbs powered by a rechargeable battery. The RED visor was constructed using a #27 Roscolux filter that transmits 4% of light, and excludes light transmission at wavelengths below 600 nM. The intensity of each unit was adjusted to within -10% of specification by positioning the bulbs (which alters the focal length of the device), and/or by use of neutral density filters, as verified by with a Minolta Chroma Meter II.
OUTCOME: Total score on the SIGH-SAD (HAM-D+atypical) was our primary outcome measure. A priori we expected the 600 lux visor to be more effective.
RESULTS: Total SIGH-SAD scores declined significantly during treatment (F[3, 180]=22.2,p<0.0001). In terms of percent improvement, there were no differences however between the visors (p>.6), no differences between the centers (p<.2), and no significant interaction. With the white visor, SIGH-SAD scores declined 37% between the second baseline wk and the second treatment wk. With the RED VISOR, SCORES DECLINED BY 43%. Using Terman's HAM-D remission criteria, the white visor produced remission in 36%, whereas the RED VISOR produced remission in 50%.
DISCUSSION: This study demonstrates that a dim RED LIGHT VISOR designed to be ineffective was as effective in reversing symptoms of SAD as a brighter white light visor.
THE DIM RED VISOR WAS ABOUT AS EFFECTIVE AS ANY INTENSITY WHITE VISOR USED IN PREVIOUS TRIALS.
Neither the spectral properties nor intensity of the light visor appears to have any direct bearing on its efficacy in the treatment of SAD. We need to seriously consider the possibilty that the light visor is a powerful placebo with efficacy approaching 25OO lux A.M. light. The other remote possibility is that the visor may work by illuminating a small portion of the retina that excludes the fovea, and that the rod population in this region may be sensitive to dim red light, and psychobiologically active.
Presented at the SOCIETY FOR LIGHT TREATMENT AND BIOLOGICAL RHYTHMS 4th annual conference, Bethesda, Maryland, April 30 & May 1st, 1992.
SLTBR DOES NOT ENDORSE ANY PARTICULAR PRODUCT OR COMPANY.
Several investigators have suggested that RED LIGHT may not be as
effective as other wavelengths of light, in the treatment of Seasonal
Affective Disorder (SAD). Therefore, RED LIGHT has been advanced as an
appropriate placebo for trials of efficacy of light therapy. However, most
studies have compared DIM red light and bright white from a standard light
box. Since dim white light is inferior to bright white light from a light
box,the finding that red light is less effective is not surprising. To date,
no studies have evaluated the efficacy of bright red light therapy in
SAD.
Subjects were consecutive outpatients with DSM-III-R major depression,
seasonal subtype, confirmed by the Structured Clinical Interview for
DSM-III-R. Patients received the Hamilton Rating Scale for Depression, SAD
Version (SIGH-SAD) and were included if they scored more than 12 on the
"Typical" items, or greater than 18 on all 25 items. Those subjects who were
taking psychotropic medications were included if they had been stable on
medications for at least 4 weeks. Light was delivered using Light Emitting
Diode (LED) lights mounted into the brim of a cap (HEALTH LIGHT INC.,
CANADA). Each subject was randomly allocated to receive two weeks of
either dim red (Mean lux = 86) or bright red (Mean lux = 1432) light followed
by one week washout period, and they were not aware of the exact intensity of
light they were receiving. Side effects were monitored using the Light Visor
Side Effect Questionnaire. The SIGH-SAD was repeated weekly and response
defined by a 50% reduction in both typical and atypical scores. Two patients,
one from each group, dropped out before completion of the treatment.
Of the 43 patients who completed the study, 19 had dim and 24 bright light.
There was no significant difference [in] the number of responders between
subjects treated with dim (68%) versus bright (67%), nor was there a
difference in percent change in SIGH-SAD scores. Furthermore, the percentage
number of responders in this study was similar to patients treated in previous
studies at our site using incandescent light (60%).
These findings suggest that dim and bright RED LIGHT are similarly
effective in treating SAD and that when delivered using LED light from a
light visor have equivalent efficacy as compared with previously studied light
units.
ALSO SEE ABSTRACT:
THE PHOTOTHERAPY LIGHT VISOR:
{SLTBR ABSTRACTS, VOLUME 4, 1992}
HEALTH LIGHT INC.
WHY 10,000 LUX WHITE?
In a 5 (3 USA & 2 CAN) centre study of 105 patients, intensities of 60, 600, &
3600 lux were used and the following was reported:
LIGHT VISOR TREATMENT OF SAD - SLTBR ABSTRACTS VOLUME 3 1991
In a study of 43 patients at the Clarke Institute of Psychiatry (Canada)
using RED lights of two intensities (86 lux & 1432 lux) on HEAD
MOUNTED units the following was reported:
"There was no significant difference in the number of responders between
subjects treated with dim (68%) versus bright (67%) nor was there a difference
in percent change in SIGH-SAD scores." ... "These findings suggest that dim
and bright RED light are similarly effective in treating SAD and that
when delivered using LED light from a light visor have equivalent efficacy as
compared with previously studied light units."
In a study of 49 patients comparing 600 Lux white and 30 Lux RED, the
following was reported:
THE PHOTOTHERAPY LIGHT VISOR: THERE IS MORE TO IT THAN MEETS THE EYE,
SLTBR ABSTRACTS VOLUME 4 -1992.
SIDE EFFECTS OF LIGHT THERAPY
LIGHT BOXES: Eyestrain 26% Headache 25% Insomnia 24% as reported in
Comprehensive Psychiatry 1991; 32: 147-152
LIGHT VISORS; (White Llght) Using Light Visor Side Effects Questionaire
LIGHT CAP; (Red Light) Using Light Visor Side Effects Questionaire:
Eyestrain 8% Headache 9.5% Insomnia 3% as reported in Contemporary Psychiatry
Aug/Sept 1992; 9-17
Our RED LIGHT LIGHT CAP IS IN USE AROUND THE WORLD - ISRAEL, GERMANY,
AUSTRALIA, ENGLAND, JAPAN, SIBERIA, INDIA, AUSTRIA as well as USA and CANADA.
Phone for information about our new Light Therapy unit the THERA CLIP
which can be clipped onto a pair of glasses or a cap or visor. It comes in a
glasses case (including the charger) for portability.
HEALTH LIGHT INC.
THERE IS MORE TO IT THAN MEETS THE EYE.
P.O. Box 3899, Station C
Hamilton, Ontario, Canada L8H 7P2
Phone/Fax 416 545-4997
"There was no significant difference between the three Intensities of light
visor treatment on absolute or percentage change SIGH-SAD scores. Furthermore,
when Patients were classified as responders versus nonresponders by various
criteria, no significant differences between light Intensities were noted." -
"Our findings suggest that intensities of light visor treatment do not affect
the efficacy of light therapy for seasonal affective disorder."
ABSTRACT FROM PRESENTATION @ CANADIAN PSYCHIATRIC ASSOCIATION 1992
"With the white visor, SIGH-SAD scores declined 37% ... With the RED
visor, scores declined by 43%"..."the white visor produced remission in
36%, whereas the RED visor produced remission in 50%." ... "The
dim RED visor was about as effective as any intensity white visor
used in previous trials."
Eyestrain 17% Headache 19% Insomnia 10% as reported in Am. J.
Psychiatry 1993; 150:4: 650-652
P.O. Box 3899, Station C.
Hamilton ON. Canada L8H 7P2
1-800-265-6020
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