Bright light therapy (BLT) has been found to be effective in treatment of seasonal affective disorder (SAD). The mechanism of action of conventional BLT in the treatment of SAD is under debate. Recently, transcranial bright light (TBL) via ear canals has been proved to modulate the neural networks of the human brain and improve cognitive performance in healthy subjects. Moreover, TBL has been found to alleviate symptoms of SAD in open trial. In this case the investigators will study the effect of transcranial bright light treatment via ear canals on depressive and anxiety symptoms in patients suffering from SAD in randomized controlled double-blind study design.

Inclusion Criteria:

• patient has (according to the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision [DSM-IV-TR]) a Major depression, recurrent episode, seasonal pattern
• Structured Interview Guide for the Hamilton Depression Rating Scale - Seasonal Affective Disorder Version Self Rating Version (SIGH-SAD-SR) score ≥ 16
• patient is over 18 years and under 66 years
• patient can read and understand the subject information sheet
• patient has signed the informed consent form
• patient is not pregnant

Exclusion Criteria:

• patient has a lifetime psychotic disorder
• patient has a bipolar disorder
• patient has alcohol or some other substance use dependence or misuse
• patient has some unstable somatic disorder
• patient uses some psychotropic agencies
• patient is, in the opinion of the investigator, unsuitable for any reason
• patient is a member of the site personnel or their immediate families
• patient has administered bright light therapy via ear canals during the current episode