Food addiction and symptoms of depression among inhabitants of the European North of Russia: Associations with sleep characteristics and photoperiod.

The purpose of this investigation was to study the sleep-wake rhythm characteristics of young persons with food addiction (FA) and symptoms of depression. A total of 2,360 young persons living in northern European Russia were included in the study. The average age of the respondents (± standard deviation [SD]) was 17.9 [4.6] years (66.6% female). Each participant provided personal data and filled in three questionnaires: the Munich Chronotype Questionnaire, the Zung Self-Rating Depression Scale, and the Yale Food Addiction Scale. FA was detected in 8.9% of respondents, and moderate-to-severe symptoms of depression were detected in 16.7% of respondents. FA and depressive symptoms were more often detected in females. Age and body mass index were shown to be significantly associated with FA. There were positive associations between the time of sunrise and FA and depressive symptoms. Persons who had symptoms of depression also tended to have a later chronotype, lower sleep efficiency, later sleep onset, higher sleep inertia, and greater sleep latency on school days. A positive relationship between FA and the time of sleep onset on school days was also revealed. Thus, the results indicate that prolonged wakefulness in the evening after sunset was associated with FA.