Bidirectional association between sleep quality or duration and aggressive behaviour in early adolescents: A cross-lagged longitudinal study

Several cross-sectional studies have suggested a strongly positive link between sleep and aggressive behaviour; however, longitudinal studies reporting the relationship between sleep and aggressive behaviour are lacking. This study aimed to examine whether a bidirectional relationship exists between sleep quality or duration and aggressive behaviour in early adolescents.A total of 1579 early adolescents (60.9 % boys) from the Chinese Early Adolescents Cohort study were included in this study. Data on sleep quality, sleep duration and aggressive behaviour collected at two time points (September 2019 and September 2021) were used, and the bidirectional relationship between sleep quality or duration and aggressive behaviour was examined using a cross-lagged model.The results revealed a bidirectional relationship between low sleep quality and highly aggressive behaviour. A shorter sleep duration did not predict highly aggressive behaviour, whereas only highly aggressive behaviour predicted a shorter sleep duration.Sleep quality and aggressive behaviour were interrelated over time among adolescents. However, sleep duration did not predict aggressive behaviour, suggesting that sleep quality, instead of sleep duration, should be the primary target for managing aggressive behaviour.