The diagnosis of major depression will be made by the Mini International Neuropsychiatric Interview (M.I.N.I.). Severity of depression will be assessed by weekly ratings using the interview-based Hamilton Depression Rating scales (17 and 6 items versions, Bech et al 2000) and the newly developed 6 item self-assessment Hamilton scale. Patients will fill in the Global Rating Scale (Preskorn) daily. Side effects will be monitored weekly by the UKU scale. At baseline, the Morningness Eveningness Questionnaire (MEQ) will be used to calculate the individual timing of light.