Sleep problems were found to positively mediate the effects of peer victimization on depressive symptoms, and were significant in female adolescents, according to study results published in the Journal of Affective Disorders. Additionally, older age was shown to increase the effect of peer victimization on sleep problems in adolescents.
The investigators of this study sought to explore whether sleep problems in adolescents play a mediating role in the relationship between peer victimization and depressive symptoms, and further if direct and indirect effects vary across age and gender groups.
The study sample included 4072 adolescents aged 14 to 19 years from the Child and Adolescent Behaviors in Long-term Evolution project in northern Taiwan. All participants completed the 2009 survey (T1), including questions used to assess the frequency at which individuals experienced peer victimization, and had available data on depressive symptoms in 2011 (T3). The participants further reported any sleep problems in 2009 and 2010 surveys (T1 and T2). The investigators performed mediation analyses to test the associations between peer victimization and sleep problems, between sleep problems and depressive symptoms, and between victimization and depressive symptoms in both male and female participants. Moderated mediation analyses were then used to examine the influence of age on direct and indirect effects of peer victimization on depressive symptoms.
Participants who reported peer victimization at T1 were significantly more likely to report increased depressive symptoms at T3, as well as higher levels of sleep problems at T2; and sleep problems at T2 were significantly associated with depressive symptoms at T3.
In mediation analyses, sleep problems were positively associated with the process linking peer victimization to depressive symptoms, but this effect was only significant among adolescent females. Age further moderated the indirect effect of peer victimization on depressive symptoms through sleep problems, in which the mediating effects of sleep problems increased with age and were significant only in older female adolescents. The direct effects of peer victimization on depressive symptoms were not influenced by age for either male or female participants.
Limitations to the study included self-reported measures for all variables and the fact that the nature of the study design does not infer causality between outcome measures.
The investigators concluded that sleep problems positively affected depressive symptoms associated with peer victimization, but were only significant in older female adolescents. They suggest that clinicians may target sleep problems to prevent or diminish depression in older female adolescents who experience peer victimization.
Chang LY, Wu CC, Lin LN, Chang HY, Yen LL. Age and sex differences in the effects of peer victimization on depressive symptoms: exploring sleep problems as a mediator. J Affect Disord. 2018. 245:553-560.