Light room therapy effective in mild forms of seasonal affective disorder--a randomised controlled study.
BACKGROUND
The most common way to provide bright light therapy to Swedish patients with Seasonal Affective Disorder (SAD), is treatment in a light therapy room. Since few studies have evaluated treatment provided in this setting and few have evaluated the effect of bright light in sub-clinical SAD (S-SAD), such a study including a one-month follow-up was designed.


METHODS
Fifty adults recruited from a previous prevalence study and clinically assessed as having SAD or S-SAD, were randomised to treatment in a light room or to a three-week waiting-list control group. The Hamilton Depression Rating Scale-Seasonal Affective Disorders Self-rating 29-items Version (SIGH-SAD/SR) was used to measure depressive mood at baseline, directly following treatment and at the one-month follow-up.


RESULTS
ANCOVA with adjustment for baseline depression score, showed a significant main effect for the light room therapy group (p<0.001). Fifty-four percent (n=13/24) improved > or = 50% while no such improvement was seen in the control condition (n=0/24). After merging the two groups, repeated measures ANOVA confirmed the experimental analysis (p<0.001). At the one-month follow-up, 83.0% (n=39/47) had improved > or = 50% and 63.8% (n=30/47) had normal depression scores, i.e. < or = 8.


CONCLUSIONS
Light room therapy was effective in reducing depressive symptoms in subjects with winter depressive mood. Results were maintained over a period of one month.
Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden. cecilia.rastad@ltdalarna.se
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Rastad
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Ulfberg
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Lindberg
D000328:Adult; D000368:Aged; D001108:Architecture; D004777:Environment; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010789:Phototherapy / Q000379:methods*; D015995:Prevalence; D016574:Seasonal Affective Disorder / Q000175:diagnosis / Q000523:psychology* / Q000628:therapy*; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires