The phototherapy light visor: More to it than meets the eye

Department of Psychiatry, Harvard Medical School, Boston, USA.
American Journal of Psychiatry (Impact Factor: 13.56). 09/1995; 152(8):1197-202.
Source: PubMed

ABSTRACT 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.
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.
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.
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.

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Available from: Martin Teicher, Aug 19, 2015
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    • "The evaluations of initial expectancy scores in the visor studies indicated that the patients had the same expectations for therapeutic effects of proposed active and placebo treatments (i.e. Teicher et al. 1995). Consequently, these results of the studies with headmounted devices showed that clinical outcome is not related to intensity, color or duration of light. "
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    ABSTRACT: Although bright light treatment may alleviate the symptoms of winter depression, it still remains to be clarified whether chronobiological mechanisms are involved in this antidepressant response. We studied the therapeutic action of bright light in 61 women with and 36 women without winter depression at the medical academic hospital near Novosibirsk (55 degrees North). Bright light was administered with cool-white incandescent lamp for seven days, two hours daily. The treatment started from either 8:00 (n = 29 patients and 16 controls) or 16:00 (n = 24 and 14, respectively) or 18:00 (n = 8 and 6, respectively). The subsets of bright light-treated subjects were then restudied in wintertime before and after one-week vacation in Firuza resort (south of Turkmeniya, 38 degrees North) (n = 19 and 0, respectively), in summertime (n = 42 and 18, respectively) and in the next winter before and after a week 30-min exposure in the morning hours to dim red light emitting ''Light Cap'' (n = 9 and 0, respectively). The results suggest that, in controls, mood slightly but statistically significantly improved after light treatment and in summer. In patients, the improvement of mood after one week of bright light was comparable with the effects of such ''natural'' treatments as trips south and transition from winter to summer seasons. Although next winter response to 0.5-h dim light was clinically significant, it was significantly worse compared to the previous response to 2-h bright light. Our therapeutic results indicate that, despite the different potential phase-shifting effect of bright light administered in the morning and in the second half of the day, the responses to all treatments are equally beneficial. This finding provides evidence against the view that circadian phase shifts are the key to the pathogenesis of winter depression and efficacy of light therapy. Although several different physiological effects of light therapy might be involved in the antidepressant response, none of them seems to be of more importance compared to psychological components of this response. Ours and earlier published reports on the independence of beneficial action of bright light from treatment timing support the suggestion that, in the open investigational trials, the placebo effect accounts for a large portion of the antidepressant response. We also reviewed several facts pointing to the close dependence of antidepressant effects of non-drug therapy upon patients' expectations and researchers' enthusiasm. In sum, unlike patients' chronobiology, their psychology seems to be most powerful mediator of the clinical response to bright light.
    Biological Rhythm Research 12/2005; 36(5). DOI:10.1080/09291010500218506 · 1.22 Impact Factor
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    • "To our knowledge, only six studies have examined the antidepressant response to bright light therapy with a credible placebo control treatment that produced similar expectations for improvement as the bright light treatment. Three of these studies used head-mounted light visors and compared bright white light to dimmer light (Joffe et al., 1993; Rosenthal et al., 1993; Teicher et al., 1995). Another study used head-mounted light visors but compared bright red light to dimmer red light (Levitt et al., 1994). "
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    ABSTRACT: Bright light is the recommended treatment for winter seasonal affective disorder (SAD). Previously we showed that the antidepressant effect of morning (but not evening) light was greater than placebo after 3 weeks of treatment. Here, we determined if the magnitude and direction of circadian rhythm phase shifts produced by the bright light in the previous study were related to the antidepressant effects. Twenty-six SAD patients from the original sample of 96 had their rectal temperature continuously monitored while they participated in a placebo-controlled parallel design conducted over six winters. After a baseline week, there were three treatments for 4 weeks-morning light, evening light, or morning placebo. Bright light was produced by light boxes (approximately 6000 lux). Placebos were sham negative ion generators. All treatments were 1.5 h in duration. Depression ratings were made weekly by blind raters. Circadian phase shifts were determined from changes in the timing of the core body temperature minimum (Tmin). Morning light advanced and evening light delayed the Tmin by about 1 h. The placebo treatment did not alter circadian phase. As the sleep schedule was held constant, morning light increased and evening light decreased the Tmin to wake interval, or phase angle between circadian rhythms and sleep. Phase advance shifts and increases in the phase angle were only weakly associated with antidepressant response. However, there was an inverted U-shaped function showing that regardless of treatment assignment the greatest antidepressant effects occurred when the phase angle was about 3h, and that patients who moved closer to this phase angle benefited more than those who moved farther from it. However 46% of our sample had a phase angle within 30 min of this 3 h interval at baseline. So it does not appear that an abnormal phase angle can entirely account for the etiology of SAD. A majority (75%) of the responders by strict joint criteria had a phase angle within this range after treatment, so it appears that obtaining the ideal phase relationship may account for some, but not all of the antidepressant response. In any case, regardless of the mechanism for the antidepressant effect of morning light, it can be enhanced when patients sleep at the ideal circadian phase and reduced when they sleep at a more abnormal circadian phase.
    Chronobiology International 08/2004; 21(4-5):759-75. DOI:10.1081/CBI-200025979 · 2.88 Impact Factor
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    • "Head mounted light devices may overcome these difficulties associated with light boxes. The greatest use of head mounted light devices has been in the treatment of seasonal affective disorders (SAD) [Stewart et al., 1990; Joffe et al., 1993; Rosenthal et al., 1993; Levitt et al., 1994; Teichner et al., 1995; Zammit et al., 2000]. Although a phase shifting hypothesis has been proposed for SAD [Lewy et al., 1998], none of these "
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    ABSTRACT: Two portable light sources, comprising light emitting diodes (LEDs) of two different wavelengths, were compared to a standard light box in suppressing and phase shifting nocturnal salivary melatonin. All light sources were equated for illuminance of 2000 lux. Sixty-six volunteers participated in the 2-day study and were randomly allocated to one of four conditions; light box, white LED, blue/green LED, or no light control group. Light was administered to the experimental groups from midnight to 02.00 hr on the first night. Half-hourly saliva samples were collected from 19.00 to 02.00 hr on night 1 and until 01.00 hr on night 2. Percent melatonin suppression on night 1 and dim light melatonin onset (DLMO) for each night were calculated. The experimental groups showed significant melatonin suppression during light stimulation, with the blue/green LEDs producing the greatest (70%) suppression. There was no significant difference between the light box at 63% and white LED at 50% suppression. Similarly, the blue/green LED had a significantly greater DLMO delay of 42 min and no difference between the light box of 23 min and the white LED of 22 min. These data suggest the portable LED light source is an effective way of delivering light to phase shift the melatonin rhythm, with the blue/green LED being the more effective of the two LEDs.
    Journal of Pineal Research 12/2001; 31(4):350-5. · 7.81 Impact Factor
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