Interconnection between adolescents' and family members' sleep.

Deficient sleep has been linked to a broad range of physical, cognitive and mental health impacts, in particular during adolescence. It is thus essential to understand its underlying mechanisms, including family factors. The goal of our study was to assess through combined subjective and objective assessments, how family members' daily variations in sleep are interconnected, between parents and siblings of adolescents. A total of 111 participants within 30 families were included, of whom 30 adolescents (14.5 years +/- 2.1 years, 46.7% boys), 30 siblings (12.8 years + /- 3.8, 40% boys), 30 mothers (43.5 years +/- 5.5) and 21 fathers (47.5 years +/- 7.6). Sleep was objectively assessed using parallel actigraphy recordings during a single week for all family members. Adolescents' daily variation in sleep duration and timing displayed many concordances with their siblings' and their mothers' sleep, but not with their fathers' sleep. Adolescents whose parents did not set limits on sleep time or screen use went to bed over an hour later (p < 0.001) and slept over 30 min less on school nights. Our study demonstrates the important role of family sleep on adolescent sleep, through rule-setting and congruence between each family members sleep, in particular regarding sleep duration and timing.