Dawn simulation and bright light in the treatment of SAD: a controlled study

Avery DH, Eder DN, Bolte MA, Hellekson CJ, Dunner DL, Vitiello MV, Prinz PN.

Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Harborview Medical Center, Seattle, Washington 98104-2499, USA.

BACKGROUND: Some small controlled studies have found that dawn simulation is effective in treating seasonal affective disorder (SAD). With a larger sample size and a longer duration of treatment, we compared dawn simulation with bright light therapy and a placebo condition in patients with SAD. METHOD: Medication-free patients with SAD were randomly assigned to one of three conditions: bright light therapy (10,000 lux for 30 min, from 6:00 AM to 6:30 AM), dawn simulation (1.5 hour dawn signal from 4:30 AM to 6:00 AM peaking at 250 lux), and a placebo condition, a dim red light (1.5 hour dawn signal from 4:30 am to 6:00 AM peaking at 0.5 lux.) Over the subsequent 6 weeks, the subjects were blindly rated by a psychiatrist using the Structured Interview Guide for the Hamilton Depression Rating-Seasonal Affective Disorder Version (SIGH-SAD). We modeled the profiles of the remissions (SIGH-SAD < or = 8) and response (> or =50% decrease in SIGH-SAD) to treatment over time using Cox proportional hazards models. RESULTS: The sample consisted of 95 subjects who were randomized to the three conditions: bright light (n = 33), dawn simulation (n = 31) and placebo (n = 31). Dawn simulation was associated with greater remission (p <.05) and response (p <.001) rates compared to the placebo. Bright light did not differ significantly from the placebo. Dawn simulation was associated with greater remission (p <.01) and response (p <.001) rates compared to the bright light therapy. The mean daily hours of sunshine during the week before each visit were associated with a significant increase in likelihood of both remission (p <.001) and response (p <.001). CONCLUSIONS: Dawn simulation was associated with greater remission and response rates compared to the placebo and compared to bright light therapy. The hours of sunshine during the week before each assessment were associated with a positive clinical response.

J Am Acad Child Adolesc Psychiatry. 1997 Jun;36(6):816-21.

Gradual versus rapid dawn simulation treatment of winter depression

Avery DH, Bolte MA, Cohen S, Millet MS.

Department of Psychiatry, School of Medicine, University of Washington, Seattle.

BACKGROUND: Bright light therapy has been shown to be effective in treating winter depression. Dawn simulation, a low-illuminance light that gradually increases in intensity while the person sleeps, decreased depression in an uncontrolled study. The present study compares a gradual dawn signal with a hypothesized placebo condition, a rapid dawn signal. METHOD: In a 4-week, randomized crossover design, nine patients with winter depression were treated with a gradual, 2.5-hour dawn simulation for 1 week and a rapid, 10-minute dawn simulation for 1 week. Both dawns had a maximum illuminance of 275 lux. At the end of each baseline week and treatment week, blind raters assessed the level of depression. RESULTS: Hamilton Rating Scale for Depression mean scores significantly decreased for both the gradual dawn (17.7 to 5.9, p < .05) and the rapid dawn (17.2 to 7.0, p < .05) condition. The improvement was similar for both treatments. Early morning awakening was significantly (p < .01) more common with the gradual dawn (7/9) than with the rapid dawn (1/9) condition. CONCLUSION: Depression decreased under both dawn simulations. Because the degree of improvement was similar, a mere placebo effect is an unlikely explanation. The degree of improvement was similar to that shown in studies of bright light therapy and clearly superior to previous "placebo" control conditions.

Dawn-dusk simulation light therapy of disturbed circadian rest-activity cycles in demented elderly

Fontana Gasio P, Krauchi K, Cajochen C, Someren E, Amrhein I, Pache M, Savaskan E, Wirz-Justice A.

Centre for Chronobiology, Psychiatric University Clinic, Basel, Switzerland.

We investigated whether low intensity dawn-dusk simulation (DDS), a 'naturalistic' form of light therapy designed to embed sleep in its accustomed phase, could improve the disturbed circadian rest-activity cycle, nocturnal sleep and and/or cognitive functions in dementia. A protocol of 3 weeks each of baseline, treatment and follow-up was completed by 13 patients (85yr old+/-5yr, MMSE 14+/-5; n=9 DDS versus n=4 'placebo' dim red light) who wore an activity/lux monitor throughout. There were no significant changes in clinical or cognitive status, nor modification of circadian stability or amplitude characteristics of the rest-activity cycle. However, two aspects of sleep responded to DDS but not to dim red light. The main sleep episode was 1:14h earlier during treatment (p=0.03) compared with before and after DDS. With respect to actimetry-determined sleep variables, the DDS group tended to have shortened 'sleep latency', longer 'sleep duration', more nocturnal immobility and less nocturnal activity than the dim red group (p<0.1). In parallel, nighttime light exposure tended to be reduced (p=0.07). These promising findings-after only 3 weeks of light treatment in elderly patients with advanced dementia-suggest that the circadian timing system remains functionally responsive even to low intensity DDS light. Increasing zeitgeber strength is an important strategy for improving sleep quality and timing in dementia, and DDS light therapy may provide one of the appropriate means to do so.

Dawn simulation vs. lightbox treatment in winter depression: a comparative study

Lingjaerde O, Foreland AR, Dankertsen J.

Department of Research and Education, Gaustad Hospital, Oslo, Norway.

Dawn simulation, with gradually increasing bedside light in the morning, has shown promising results as an alternative to bright light treatment for winter depression. To compare these treatments, 61 out-patients with winter depression (20-70 years of age, 80% women) were randomized to receive either lightbox treatment with 1500-2500 lux white light for 2 h in the morning for 6 days on an out-patient basis (n=34), or dawn simulation treatment in their homes, with 60 or 90 min of light augmentation time to 100-300 lux, for 2 weeks (n=27). Patients' ratings of improvement on a visual analogue scale (correlating strongly with percentage reduction in an extended Montgomery-Asberg Depression Rating Scale (MADRS) score) at the end of treatment showed a mean of 40.0% (SD 27.7%) in the dawn simulation group and 57.4% (SD 29.9%) in the lightbox group (P=0.02). The majority of the patients in both groups maintained their improvement during a 9-week follow-up. Age, sex, current major depression or current use of antidepressants did not predict outcome in either group. No serious side-effects were observed.

A controlled trial of light therapy for the treatment of pediatric seasonal affective disorder

Swedo SE, Allen AJ, Glod CA, Clark CH, Teicher MH, Richter D, Hoffman C, Hamburger SD, Dow S, Brown C, Rosenthal NE.

Department of Psychiatry, McLean Hospital, Belmont, MA, USA.

OBJECTIVE: To evaluate the efficacy of light therapy for the treatment of pediatric seasonal affective disorder (SAD). METHOD: 28 children (aged 7 to 17 years) at two geographically distinct sites were enrolled in a double-blind, placebo-controlled, crossover trial of bright-light treatment. Subjects initially entered a week-long baseline period during which they wore dark glasses for an hour a day. They were then randomly assigned to receive either active treatment (1 hour of bright-light therapy plus 2 hours of dawn simulation) or placebo (1 hour of clear goggles plus 5 minutes of low-intensity dawn simulation) for 1 week. The treatment phase was followed by a second dark-glasses phase lasting 1 to 2 weeks. After this phase, the children received the alternate treatment. Response was measured using the parent and child versions of the Structured Interview Guide for the Hamilton Depression Rating Scale, Seasonal Affective Disorders version (SIGH-SAD). RESULTS: Data were analyzed as change from baseline. SIGH-SAD-P total depression scores were significantly decreased from baseline during light therapy compared with placebo (one-way analysis of variance, rho = .009), and no differences were found between the placebo and control phases. Subscores of atypical and typical depression were also significantly decreased during the active treatment (rho = .004 and .028, respectively). A similar trend was noted with the SIGH-SAD-C, but this did not reach significance. At the end of the study, 78% of the parents questioned and 80% of the children questioned rated light therapy as the phase during which the child "felt best." CONCLUSION: Light therapy appears to be an effective treatment for pediatric SAD.

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