Bright dawn simulation compared with bright morning light in the treatment of winter . depression 1
Avery D, Bolte MA, Millet M. Bright dawn simulation compared with bright morning light in the treatment of winter depression. Acta Psychiatr Scand 1992: 85: 430-434. In a randomized cross-over design, 7 patients with winter depression were treated with a week of a bright (1700 lx) dawn simulation (0400 to 0600) and a week of standard bright (1700 Ix) morning (0600 to 0800) light therapy. The Hamilton Rating Scale for Depression scores decreased significactly for the standard light therapy (18.9 to 6.6) but not for the bright dawn therapy (18.0 to 11.3). Early morning awakening was a frequent side effect with the bright dawn simulation. Although dawn simulation at a lower illuminance may be an effective treatment, the bright dawn used in this study showed only a nonsignificant trend to lower depression ratings. The illuminance of dawn simulation should be adjusted to minimize side effects.
Bright light (greater than 2000 lx) has been shown to be effective in the treatment of winter depression compared with dim (100-400 lx) light conditions (1-3). Terman et al. (4, 5 ) reported preliminary data suggesting that dawn simulation, a lower level of light increasing gradually in illuminance during sleep, might also be effective for winter depression. This study compares bright dawn simulation with standard bright light therapy. Material and methods
The subjects were recruited through advertisements and through publicity concerning our program. Subjects fulfilled criteria for major depressive episode with seasonal pattern according to DSM-111-R (6) as well as primary affective disorder according to Feighner criteria (7). Subjects also fulfilled Rosenthal criteria for seasonal affective disorder (SAD) (1). Subjects reported regularly occurring autumn-winter depressions (with at least 2 occurring during consecutive winters) remitting during the spring or summer. In addition, no psychosocial variables could account for the regular changes in mood. All had hypersomnia as part of their winter depression. All subjects were free of any psychotropic medication for at least 2 weeks prior to the study. Subjects gave written informed consent. During the 4-week study, subjects were asked to sleep only between the hours of 2100 and 0600 and keep a log of their sleep. The first week was a baseline week during which
430
D.Avery ’, M.A. Bolte’, M. Millet2
’
Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Department of Architecture, University of Washington, Seattle, USA
Key words: seasonal affective disorder; light treatment David H. Avery. M.D., Harborview Medical Center, ZA-99, 325 9th Ave, Seattle, WA 98104, USA Accepted for publication December 29, 1991
no light treatment was administered. At the beginning of the second week, the subjects were randomly assigned to either a bright gradual dawn simulation over a 2-h period or standard morning bright light treatment. During the third week, the subjects received no treatment. During the fourth week the subjects were crossed over to the light treatment they did not receive during the second week. Both light treatments used 2 150-W incandescent reflector flood lights (Phillips) that were 0.9 m from the eyes so that an illuminance of 1700 lx was obtained. When subjects used the lights as a standard bright light treatment, they sat in front of the lights from 0600 to 0800 and were allowed to read, watch TV, etc. The standard bright therapy differed from the bright light therapy commonly used in that incandescent lights were used rather than fluorescent tubes and the 1700 lx intensity was slightly less than the 2500 lx illuminance frequently used. The gradual bright dawn simulation consisted of a gradually increasing illuminance (approximately 2.6 log,,, lx/h) of light from 0400 to the maximum intensity of 1700 lx at 0600. The incandescent light was plugged into a dawn simulator device (SunRiser Enterprises, Seattle, WA, USA) that creates a gradually increasing voltage starting at a specified time. Subjects were asked to sleep until 0600; at this time they were awakened by an alarm. If they awoke before 0600, they were asked to avoid looking at the lights, close their eyes and try to go back to sleep. Subjects used these lights daily during their respective treatment weeks.
Dawn vs bright light in SAD The bedrooms of the subjects were required to be dark. If a street light or security light did shine through the bedroom windows, subjects were given sheets of black plastic to cover the windows. Subjects were asked to turn off any nightlights or hall lights that might shed light into the bedroom. These hypersomnic subjects typically slept throughout the night and did not need to get up to the bathroom. If this occurred, they would attempt to do so only with a nightlight in their bathroom. They were advised to avoid morning sunlight before 0800 during the entire study. Expectations of the response to gradual dawn simulation and rapid dawn simulation were assessed at baseline. They rated their expected response to rapid dawn simulation and to gradual dawn simulation on a global scale (1 = worse, 2 = no change, 3 = slight improvement, 4 = much improvement and 5 = very much improved). At the end of each light treatment, subjects rated their own response to light treatment on a similar global scale (1 = worse, 5 = very much improved). They also rated their expectations of the relative efficacy of rapid dawn simulation and gradual dawn simulation on a 7-point scale: 1 = bright dawn light very much better than standard light therapy, 2 = bright dawn light much better, 3 = bright dawn light slightly better, 4 = bright dawn light equal to standard light therapy, 5 = standard light therapy slightly better than bright dawn light, 6 = standard light therapy dawn light much better and 7 = standard light therapy very much better. After the subjects had completed both dawn simulations, they compared the responses to the two treatments with a scale similar to the 7-point expectation scale. Subjects were rated blindly by experienced psychiatrists using the Structured Interview for the Hamilton Depression Rating Scale-Seasonal Affective Disorder Version (SIGH-SAD) which includes the 21-item Hamilton Rating Scale for Depression (HRSD) (8) and supplementary questions concerning atypical depressive symptoms common in SAD such as hypersomnia and increased appetite (9). Subjects were also systematically asked about possible side effects: early morning awakening, headache, agitation, evening drowsiness, irritability and tight muscles. The each item was rated as: none, mild, moderate or severe. Statistical analysis induced 2-factor analysis of variance (ANOVA) and 1-sample and 2-sample t-tests. Results
Nine women and 1 man with a mean age of 39 10 (range 29-59) years qualified for the study. One fulfilled criteria for a hypomanic syndrome during the
summer. Seven had taken either antidepressant or antianxiety medication for previous depressions. Five were randomized to each light condition as the first treatment. Seven completed the protocol. One subject responded to the bright dawn, but did not return after the standard light therapy. Another responded well to the standard light therapy but did not return for the bright dawn. A third patient was noncompliant with the standard light treatment. The data were analyzed using a 2-factor ANOVA design, one factor being the subject groups defined by order of treatment conditions, bright dawn first (n = 4) vs standard bright light therapy first ( M = 3), the other being repeated measures on the HRSD and SAD subscale scores. Two analyses were performed; the first analyzed the baseline scores administered before the first and second interventions. This analysis checks for whether the 2 subject groups (defined by order) differ in the overall baseline depression levels and whether the period between interventions is sufficient to allow the subjects to return to their original baseline. Thus, this analysis serves as a check on: (a) whether the 2 groups, although randomly assigned, differ in their initial condition and (b) whether there were any carry-over effects in the cross-over design. The second analysis used the same design, except that the dependent variables were the repeated HRSD and SAD subscale scores following the first and second interventions. The results of the ANOVA analysis are summarized in Table 1. The 2 subject groups defined by order were similar in their baseline scores. The main baseline scores in the first and second interventions are similar except that, for the SAD subscale, the second baseline score was lower than the first baseline score (P< 0.01). The group x time interaction of the baseline scores was nonsignificant. The HRSD results support the statistical superiority (P< 0.05) of the standard bright light therapy. The interaction of the SAD subscale showed a nonsignificant trend (P = 0.08). The standard bright light therapy significantly decreased both the HRSD score ( t = 4.75, Bonferroni P
Avery D, Bolte MA, Millet M. Bright dawn simulation compared with bright morning light in the treatment of winter depression. Acta Psychiatr Scand 1992: 85: 430-434. In a randomized cross-over design, 7 patients with winter depression were treated with a week of a bright (1700 lx) dawn simulation (0400 to 0600) and a week of standard bright (1700 Ix) morning (0600 to 0800) light therapy. The Hamilton Rating Scale for Depression scores decreased significactly for the standard light therapy (18.9 to 6.6) but not for the bright dawn therapy (18.0 to 11.3). Early morning awakening was a frequent side effect with the bright dawn simulation. Although dawn simulation at a lower illuminance may be an effective treatment, the bright dawn used in this study showed only a nonsignificant trend to lower depression ratings. The illuminance of dawn simulation should be adjusted to minimize side effects.
Bright light (greater than 2000 lx) has been shown to be effective in the treatment of winter depression compared with dim (100-400 lx) light conditions (1-3). Terman et al. (4, 5 ) reported preliminary data suggesting that dawn simulation, a lower level of light increasing gradually in illuminance during sleep, might also be effective for winter depression. This study compares bright dawn simulation with standard bright light therapy. Material and methods
The subjects were recruited through advertisements and through publicity concerning our program. Subjects fulfilled criteria for major depressive episode with seasonal pattern according to DSM-111-R (6) as well as primary affective disorder according to Feighner criteria (7). Subjects also fulfilled Rosenthal criteria for seasonal affective disorder (SAD) (1). Subjects reported regularly occurring autumn-winter depressions (with at least 2 occurring during consecutive winters) remitting during the spring or summer. In addition, no psychosocial variables could account for the regular changes in mood. All had hypersomnia as part of their winter depression. All subjects were free of any psychotropic medication for at least 2 weeks prior to the study. Subjects gave written informed consent. During the 4-week study, subjects were asked to sleep only between the hours of 2100 and 0600 and keep a log of their sleep. The first week was a baseline week during which
430
D.Avery ’, M.A. Bolte’, M. Millet2
’
Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Department of Architecture, University of Washington, Seattle, USA
Key words: seasonal affective disorder; light treatment David H. Avery. M.D., Harborview Medical Center, ZA-99, 325 9th Ave, Seattle, WA 98104, USA Accepted for publication December 29, 1991
no light treatment was administered. At the beginning of the second week, the subjects were randomly assigned to either a bright gradual dawn simulation over a 2-h period or standard morning bright light treatment. During the third week, the subjects received no treatment. During the fourth week the subjects were crossed over to the light treatment they did not receive during the second week. Both light treatments used 2 150-W incandescent reflector flood lights (Phillips) that were 0.9 m from the eyes so that an illuminance of 1700 lx was obtained. When subjects used the lights as a standard bright light treatment, they sat in front of the lights from 0600 to 0800 and were allowed to read, watch TV, etc. The standard bright therapy differed from the bright light therapy commonly used in that incandescent lights were used rather than fluorescent tubes and the 1700 lx intensity was slightly less than the 2500 lx illuminance frequently used. The gradual bright dawn simulation consisted of a gradually increasing illuminance (approximately 2.6 log,,, lx/h) of light from 0400 to the maximum intensity of 1700 lx at 0600. The incandescent light was plugged into a dawn simulator device (SunRiser Enterprises, Seattle, WA, USA) that creates a gradually increasing voltage starting at a specified time. Subjects were asked to sleep until 0600; at this time they were awakened by an alarm. If they awoke before 0600, they were asked to avoid looking at the lights, close their eyes and try to go back to sleep. Subjects used these lights daily during their respective treatment weeks.
Dawn vs bright light in SAD The bedrooms of the subjects were required to be dark. If a street light or security light did shine through the bedroom windows, subjects were given sheets of black plastic to cover the windows. Subjects were asked to turn off any nightlights or hall lights that might shed light into the bedroom. These hypersomnic subjects typically slept throughout the night and did not need to get up to the bathroom. If this occurred, they would attempt to do so only with a nightlight in their bathroom. They were advised to avoid morning sunlight before 0800 during the entire study. Expectations of the response to gradual dawn simulation and rapid dawn simulation were assessed at baseline. They rated their expected response to rapid dawn simulation and to gradual dawn simulation on a global scale (1 = worse, 2 = no change, 3 = slight improvement, 4 = much improvement and 5 = very much improved). At the end of each light treatment, subjects rated their own response to light treatment on a similar global scale (1 = worse, 5 = very much improved). They also rated their expectations of the relative efficacy of rapid dawn simulation and gradual dawn simulation on a 7-point scale: 1 = bright dawn light very much better than standard light therapy, 2 = bright dawn light much better, 3 = bright dawn light slightly better, 4 = bright dawn light equal to standard light therapy, 5 = standard light therapy slightly better than bright dawn light, 6 = standard light therapy dawn light much better and 7 = standard light therapy very much better. After the subjects had completed both dawn simulations, they compared the responses to the two treatments with a scale similar to the 7-point expectation scale. Subjects were rated blindly by experienced psychiatrists using the Structured Interview for the Hamilton Depression Rating Scale-Seasonal Affective Disorder Version (SIGH-SAD) which includes the 21-item Hamilton Rating Scale for Depression (HRSD) (8) and supplementary questions concerning atypical depressive symptoms common in SAD such as hypersomnia and increased appetite (9). Subjects were also systematically asked about possible side effects: early morning awakening, headache, agitation, evening drowsiness, irritability and tight muscles. The each item was rated as: none, mild, moderate or severe. Statistical analysis induced 2-factor analysis of variance (ANOVA) and 1-sample and 2-sample t-tests. Results
Nine women and 1 man with a mean age of 39 10 (range 29-59) years qualified for the study. One fulfilled criteria for a hypomanic syndrome during the
summer. Seven had taken either antidepressant or antianxiety medication for previous depressions. Five were randomized to each light condition as the first treatment. Seven completed the protocol. One subject responded to the bright dawn, but did not return after the standard light therapy. Another responded well to the standard light therapy but did not return for the bright dawn. A third patient was noncompliant with the standard light treatment. The data were analyzed using a 2-factor ANOVA design, one factor being the subject groups defined by order of treatment conditions, bright dawn first (n = 4) vs standard bright light therapy first ( M = 3), the other being repeated measures on the HRSD and SAD subscale scores. Two analyses were performed; the first analyzed the baseline scores administered before the first and second interventions. This analysis checks for whether the 2 subject groups (defined by order) differ in the overall baseline depression levels and whether the period between interventions is sufficient to allow the subjects to return to their original baseline. Thus, this analysis serves as a check on: (a) whether the 2 groups, although randomly assigned, differ in their initial condition and (b) whether there were any carry-over effects in the cross-over design. The second analysis used the same design, except that the dependent variables were the repeated HRSD and SAD subscale scores following the first and second interventions. The results of the ANOVA analysis are summarized in Table 1. The 2 subject groups defined by order were similar in their baseline scores. The main baseline scores in the first and second interventions are similar except that, for the SAD subscale, the second baseline score was lower than the first baseline score (P< 0.01). The group x time interaction of the baseline scores was nonsignificant. The HRSD results support the statistical superiority (P< 0.05) of the standard bright light therapy. The interaction of the SAD subscale showed a nonsignificant trend (P = 0.08). The standard bright light therapy significantly decreased both the HRSD score ( t = 4.75, Bonferroni P
