AuthorsStudy Design, Population, and ObjectiveLight Intensity, Apparatus, Outcome Measure, Response CriterionResultsComments /Conclusions
Meesters et al. (1995)

Academic Hospital, Groningen, The Netherlands
Randomized crossover and parallel-group study to investigate effects of timing of light tx (differences in response rates for light exposure at different times of day; influence of short-term rank ordering of morning and evening light on response rates).

68 patients with winter SAD who were drug-free for >3 wks.

5 tx groups: 4 days of ML (I, n=14); 4 days of AL (II, n=15); 4 days of EL (III, n=12); 2 days of ML, 2 days of EL (IV, n=13); 2 days of EL, 2 days of ML (V, n=14).
10,000 lux for 30 min.

Depressed mood assessed 3 x/day by AMS and VAS-DEP and by BDI on days 2, 5, 12, 19; severity of depression assessed using HDRS.

Response criterion: Final HDRS score <8, w/ maximum of 50% of baseline score.
Response rates: I, 69%; II, 57%; III, 80% with no significant differences; IV, 67%; V, 50% with no significant differences (also no differences between these rates and I and III).

Timing of light tx does not appear to be critical; short-term rank ordering of ML and EL does not influence x/day outcome.
Wirz-Justice et al. (1996)

Psychiatric University Clinic, Basel, Switzerland
Nonrandomized controlled trial to compare effects of natural light with low-dose artificial light (placebo) and to relate clinical response to putative alterations of circadian rhythm phase.

34 volunteer patients (28 evaluable) with winter SAD.

2 tx groups: Morning natural light (n=20), morning low-dose artificial light (placebo) (n=8).
Natural light tx: Daily 1-hr early morning walk outdoors in sunlight, if present, for 1 wk.

Artificial light tx: 2800 lux for 30 min/day for 1 wk.

HDRS used to assess response: Decrease of >50% defined response, with score of <8 indicating remission of symptoms.

Salivary melatonin and cortisol measured at dusk (onset of melatonin secretion) and dawn (offset).
Natural light tx significantly reduced depressive symptomatology; 65% responded and 50% showed remission of symptoms. Artificial light tx produced response in 50% of patients and remission in 25%.

Morning walk phase-advanced onset and/or offset of salivary melatonin secretion and decreased morning cortisol. Low-dose artificial light did not modify melatonin or cortisol patterns.
Outdoor natural morning light exposure for 1 hr appears to be as effective an antidepressant as high-dose artificial morning light seen in a previous trial.
Terman et al. (1996)

Columbia University and NYS Psychiatric Institute, New York, NY
Uncontrolled cases series to determine whether pattern and severity of depressive symptoms predict response to light tx.

103 volunteer patients with winter depression with seasonal pattern.

Normal physical exam, lab results and ECG; no cataracts, glaucoma or retinal disease; free of antidepressant medications, no previous light tx.
First 2 yrs: 2500 lux fluorescent light for 2 hr daily for 7-10 days in morning, evening, or both.

After 2 yrs: 10,000 lux for 30 min daily in morning or evening for 10-14 days with crossover.

SIGH-SAD and CGI used to assess response: Responders had >50% reduction in SIGH-SAD score with score of <7 and CGI rating of 1 (very much improved) or 2 (much improved); partial responders had SIGH-SAD score reductions between 30% and 50% and CGI ratings of 3 (minimal improvement); nonresponders had SIGH-SAD score reduction <25% (or score increased) and CGI ratings of 4 (unchanged) or higher (worsened).
71 (~69%) responders; 15 (~15%) nonresponders; 17 (~17% partial responders).

Responders characterized by atypical symptoms, especially hypersomnia, afternoon or evening slump, reverse diurnal variation (evenings worse), and carbohydrate craving (effect size positive for these symptoms). Nonresponders characterized by melancholic symptoms, such as retardation, suicidality, depersonalization, typical diurnal variation (mornings worse), anxiety, early and late insomnia, appetite loss, and guilt (effect size negative). Ratio of atypical to classical symptoms of depression, not severity per se, best predicted tx outcome.
Responders and nonresponders showed different clinical profiles when depressed. Light-responsive SAD distinguished by dominant atypical symptom profile associated with depressed mood, with nonresponders forming clinically distinct group with melancholic features.

Authors question whether nonresponders should be diagnosed as having SAD. Thus, necessary to consider patient=s symptom profile in diagnosis and selecting tx for SAD.
Reichborn-Kjennerud and Lingjørde (1996)

Gaustad Hospital, Oslo, Norway
Uncontrolled case series to examine personality disorders and temperament as possible predictors of response to light therapy for SAD.

42 volunteer patients with winter SAD (33 included in part of study concerning personality disorders and temperament).

No psychotic symptoms, severe suicidal ideation, current alcohol or drug abuse, or significant somatic illness; no fluoxetine, no antidepressants for >2 wks prior.
Full-spectrum white light of 1500 lux for 2 hr each morning for 6 consecutive days (4 patients received 1 hr of tx); tx administered in specially equipped hospital room; <10 patients treated simultaneously.

Extended version MADRS* : nonresponders had pre-tx to post-tx score reduction <30%; responders showed >50% reduction.
22 (52%) responders, 8 (19%) nonresponders; responders had significantly fewer previous episodes of SAD than nonresponders.

Patients with any Axis II personality disorder were significantly less likely to respond to light therapy than those without Axis II pathology.

Poor tx outcome also significantly associated with one or more personality disorders in cluster C, avoidant personality disorder, high number of positive criteria for self-defeating personality disorder, and high score on harm avoidance scale of TPQ.
Results suggest that personality disorder and temperament factors that predict poorer response to antidepressant medication in patients with non-seasonal major depressive disorder found in other studies also predict poorer response to light tx in SAD patients.
Swedo et al. (1997)

McLean Hospital, Belmont, MA and NIMH, Bethesda, MD
Randomized, double-blind, placebo-controlled crossover trial to evaluate the efficacy of light therapy for tx of pediatric SAD.

28 volunteer children (age, 7-17 yr) with winter SAD.

2 tx groups: Active tx (1 hr bright-light therapy plus 2 hrs dawn simulation), and placebo tx (1 hr clear goggles plus 5 min low-intensity dawn simulation).
Active tx: Dawn simulation to maximum of 250 lux, bright-light (2500 lux for <9 yrs and 10,000 lux for >9 yrs) between 4 and 8 pm.

Placebo tx: Dawn simulation to maximum of 2 lux, clear goggles between 4 and 8 pm.

1 wk baseline period (dark glasses) followed by 1 wk tx phase (active or placebo) followed by 1-2 wks washout period (dark glasses) followed by 1 wk alternate tx.

SIGH-SAD-P† (n=28) and SIGH-SAD-C † (n=16) used to measure symptom severity.
SIGH-SAD-P depression scores significantly decreased from baseline during active tx compared with placebo, with no difference between placebo and control (washout) phases. Similar, but nonsignificant, trend for SIGH-SAD-C scores.

20 (71%) children had >50% decrease of symptoms during active tx compared with 7 (25%) during placebo tx.

Post-tx survey: 78% of parents and 80% of children rated active tx as the one in which the child felt best.
Comorbid psychiatric diagnoses in 10 children (36%), including ADHD, learning disorder, separation anxiety disorder, and post-traumatic stress disorder may confound results.

Preliminary results suggest bright-light therapy may be effective tx for pediatric SAD; however, future studies need to determine differential efficacy of dawn simulation and light box tx.

Active tx was not associated with higher frequency of side effects and was well tolerated.
Lingjærde et al. (1998)

Gaustad Hospital, Oslo, Norway
Randomized controlled study to compare dawn simulation with bright-light tx.

61 volunteer patients (age, 20-70 yrs) with winter SAD.

2 tx groups: Light box tx on an outpatient basis (n=34), dawn simulation tx in homes (n=27).

No current psychiatric comorbidity, abuse of alcohol or drugs during previous year, significant eye disease, or suicidal risk.
Light box tx: 1500-2500 lux full-spectrum white light for 2 hrs in morning for 6 days; given simultaneously to <7 patients in same room.

Dawn simulation tx: 60 or 90 min light augmentation time to 100-300 lux for 2 wks.

Extended MADRS used to rate severity of symptoms; VAS used to measure patient=s ratings of improvement (main outcome measure). Responders reported >50% improvement.
Immediate response showed significant difference in improvement at end of tx period on VAS (dawn simulation group, 40%; light box group, 57%) and significant difference in number of responders (dawn simulation group, 9 [33%]; light box group, 22 [65%]).

Most patients in light box group maintained immediate improvement throughout 9-wk follow-up period; however, maintenance of improvement more variable in dawn simulation group, with many showing gradual improvement, eventually reaching same improvement level as light box group.
19% of patients in dawn simulation group and 18% of patients in light box group were on current antidepressant tx.

Losses to follow-up during 10-wk follow-up period: included 9 in dawn simulation group (33%) and 6 in light box group (18%).

Results confirm authors= previous finding of marked and lasting effect of 1 wk of moderate light box tx in winter depression; 2 wks of dawn simulation appears to have a less marked but persistent effect.
Postolache et al. (1998)

NIMH, Bethesda, MD
Uncontrolled case series to compare degree of improvement after light tx with mood improvement in the subsequent summer in patients with SAD.

15 patients with winter SAD.

No comorbid Axis I psychiatric conditions, medical problems, psychotrophic medications.
10,000 lux cool-white fluorescent light for 45 min 2 × daily for 2 wks, then tx individually customized and gradually tapered in spring.

SIGH-SAD used to rate mood: Response to light defined as >50% decrease in baseline score and total post-tx <7.
Patients' scores on depression scale significantly higher after 2 wks of light therapy in winter than during following summer.Preliminary results suggest that 2 wks of light tx in winter is only partially effective when compared with summer; however, further studies are needed to determine whether summer's light or other factors are the main contributors to this difference.
Eastman et al. (1998)

Rush-Presbyterian-St. Luke's Medical Center, Chicago, IL
Randomized placebo-controlled trial using a parallel design to determine whether light tx has a benefit beyond its placebo effect.

96 volunteer patients with SAD (usual criteria plus atypical symptoms of increased appetite or weight and increased sleep).

3 tx groups: ML (n=33), EL (n=32), MP (n=31).

No complicating medical conditions, no psychotropic medications, no previous bright light or negative-ion tx; not permitted to drink alcohol or to drink caffeine within 6 hrs of earliest bedtime.
~6000 lux; light box with 6 horizontally mounted cool-white fluorescent lamps.

Placebo: Sham negative ion generator.

Both groups treated 1.5 hrs/day, 6 days/wk for 4 wks.

Depression ratings using SIGH-SAD performed weekly: Decrease in SIGH-SAD score to 50% of baseline and score of <8 (strict response criteria) identified those with complete or nearly complete remissions.
No differences in expectation ratings; no differences in mean depression scores after 4 wks (patients improved over time regardless of tx group).

Responders: ML 55%;, EL 56%, MP 52% after 3 wks tx; ML 67%; EL 75%, MP 48% after 4 wks tx.

Statistically significant differences when strict response criteria used. % responders increased as weeks progressed, and ML produced best response rates; after 4 wks, ML 61%, EL 50%, MP 32%.
71 patients were evaluable.

Bright-light tx was a better antidepressant for SAD than placebo, producing more full remissions, but difference only reached statistical significance at 3 wks.
Terman et al. (1998)

Columbia University and NYS Psychiatric Institute, New York, NY
Randomized controlled trial using crossover design (morning/evening) balanced by parallel-group controls and nonphotic controls given negative air ionization to compare response to morning and evening light with response to negative air ions and to detect potential sequence effects 158 volunteer.

patients with SAD (age, 18-65 yr) given 2 consecutive tx of 10-14 days each.

6 tx groups (2 crossover, 2 parallel, 2 nonphotic controls): ML-EL (n=27); EL-ML (n=20); ML-ML (n=19); EL-EL (n=19); high ion density both periods (H-H) (n=20); low ion density both periods (L-L) (n=19).

Normal medical status, no other Axis I disorder, no suicide attempt within 3 yrs, no habitual sleep onset later than 1 am or awakening later than 9 am; required to abstain from psychotropic medications, alcohol, recreational drugs.
10,000 lux for 30 min/day; SPX-30 triphosphor fluorescent lamps encased in a metal box with a translucent plastic diffusing screen.

Nonphotic controls treated for 30 min/day in the morning: High ion density, 2.7 × 106 ions/cm3; low ion density, 1.0 × 104 ions/cm3

Depression ratings using SIGH-SAD: Decrease in SIGH-SAD score to 50% of baseline and score of <8 (strict response criteria) identified those with complete or nearly complete remissions.
No differences in expectation ratings; no significant differences in depression scale % change scores of 5 active tx groups, but placebo control group (L-L) had significantly less improvement than other groups.

Only sequence effect was response to EL reduced when preceded by tx with ML.

Significantly higher response to ML than EL sequence using strict remission criteria, regardless of tx; remission rates during first tx period were ML 54%, EL 33% (P=0.04), H 20%, L 10.5%.
145 patients completed study; 124 patients were evaluable.

Both bright light and high-density negative air ionization act as specific antidepressants in patients with SAD; since EL produced a higher response than low-density placebo, cannot conclude that EL is inactive.
Lewy et al. (1998)

Oregon Health Sciences University, Portland, OR
Controlled trial with crossover and parallel-group comparisons to assess the antidepressant effects of morning vs evening light.

51 volunteer patients with SAD exposed to bright light for 2 hrs/day, and 49 matched controls.

2 tx groups: ML-EV and EL-ML.

Good physical health, not suicidal, no psychotropic medications or other needs that interfere with endogenous melatonin production, no psychiatric or medical illnesses.
2500 lux for 2 hrs/day for 2 wks followed by 1 wk withdrawal and then crossed over to other schedule; 2 40-watt cool-white fluorescent tubes.

DLMO used as a marker of circadian phase position.

Behavioral SIGH-SAD ratings: Remission criteria were >50% decrease in rating and post-tx score of <14.
Parallel-group comparison during first tx period showed significant difference in % change scores from baseline (ML, 36%; EL, 8%) and significant difference in number of responders (ML, 8/27 [30%]; EL, 1/24 [4%]).

Crossover group comparison combining both tx periods showed significant difference in % change scores from baseline (ML, 37%; EL, 17%) and significant difference in number of responders (ML, 19/51 [37%]; EL, 3/51 [6%]).

DLMO: Patients delayed compared with controls at all weeks of study, mainly due to ML first patient group; morning light phase-advanced DLMO and EL delayed it.
ML more antidepressant than EL for each tx period (parallel-group comparisons) and for both periods combined (crossover comparison); antidepressant superiority of ML over EL greater in second tx period than in first; lack of carryover effect may be due to withdrawal week between tx periods.

EL=s modest antidepressant effect may be due to placebo effect; however, since study lacked placebo control, this cannot be shown.

Results are consistent with phase-shift hypothesis.

* Extended with 4 items: increased sleep, increased appetite, carbohydrate craving, and fatigability. H Modified parent and child versions of † SIGH-SAD; similar to adult version but contain additional items to measure symptoms that are unique to children.

NOTE: All studies used light boxes to provide artificial light. In addition, the Wirz-Justice et al. (1996) study used natural light for the active tx group and the Lingjørde et al. (1998) study used dawn simulation as one of the active tx group

From: Light Therapy for Seasonal Affective Disorder (SAD)

Cover of Minnesota Health Technology Assessments
Minnesota Health Technology Assessments [Internet].
Minnesota Health Technology Advisory Committee.
St. Paul (MN): Minnesota Department of Health; 1995-2001.

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