Whether psychological factors are related to the onset of a novel depressive episode has been studied in 29 patients with Seasonal Affective Disorder (SAD) in remission (early autumn) and their controls: the subjects judged various emotional expressions in schematic faces with light or dark backgrounds. It was found that SAD patients show an enhanced cognitive sensitivity. The larger the difference remitted SAD patients see in emotional expression between light and dark backgrounds, the earlier they become depressed in the next late autumn and winter. Results are in line with interactional (cognitive) theories of depression and suggest that psychological factors may mediate the onset of a novel depressed episode.