'Natural' light treatment of seasonal affective disorder.
Patients with seasonal affective disorder (SAD) were treated for 1 week either with a daily 1-h morning walk outdoors (natural light) or low-dose artificial light (0.5 h@2800 lux). The latter treatment (given under double-blind conditions) can be considered mainly placebo and did not improve any of the depression self-ratings, whereas natural light exposure improved all self-ratings. According to the Hamilton depression score, 25% remitted after low-dose artificial light and 50% after the walk. Sleep duration or timing were not crucial for the therapeutic response. The morning walk phase-advanced the onset and/or offset of salivary melatonin secretion, but individual clinical improvement could not be correlated with specific phase-shifts. Morning cortisol was decreased. Low-dose artificial light did not modify melatonin or cortisol patterns. This is the first study to provide evidence for the use of outdoor light exposure as a potential alternative or adjuvant to conventional artificial light therapy in SAD.
Wirz-Justice
A
A
Psychiatric University Clinic, Basel, Switzerland.
Graw
P
P
Kräuchi
K
K
Sarrafzadeh
A
A
English
J
J
Arendt
J
J
Sand
L
L
D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D008297:Male; D008550:Melatonin / Q000378:metabolism; D008875:Middle Aged; D010555:Personality Inventory; D010789:Phototherapy / Q000379:methods*; D012463:Saliva / Q000378:metabolism; D016574:Seasonal Affective Disorder / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology / Q000628:therapy*; D012894:Sleep Stages / Q000502:physiology; D013472:Sunlight; D016896:Treatment Outcome; D016138:Walking / Q000523:psychology
D008550:Melatonin; D006854:Hydrocortisone