The aims of this study were to estimate the prevalence of Delayed Sleep Phase Syndrome (DSPS) in adolescence, and to examine the association to insomnia and school non-attendance.

Although frequently used with older adolescents, few studies of the factor structure, internal consistency and gender equivalence of the SDQ exists for this age group, with inconsistent findings. In the present study, confirmatory factor analysis (CFA) was used to evaluate the five-factor structure of the SDQ in a population sample of 10,254 16–18 year-olds from the youth@hordaland study. Measurement invariance across gender was assessed using multigroup CFA. A modestly modified five-factor solution fitted the data acceptably, accounting for one cross loading and some local dependencies. Importantly, partial measurement non-invariance was identified, with differential item functioning in eight items, and higher correlations between emotional and conduct problems for boys compared to girls. Implications for use clinically and in research are discussed.

Social media (SOME) use among adolescents has been linked to mental health and well-being. SOME self-presentation has been highlighted as an important factor to better understand the potential links. The aims of this study were to investigate the association between focus on SOME self-presentation and mental health and quality of life among adolescents. We used a cross-sectional survey, with n = 513 (56%; mean age 17.1 years; 58% boys) students from a senior high school in Norway. Associations between focus on SOME self-presentation and symptoms of anxiety and depression and quality of life were investigated using blobbograms, standardized mean difference (SMD), and gender-specific linear regression models. A high focus on SOME self-presentation was associated with more mental health problems and reduced quality of life. The strength of the associations with symptoms of depression (0.75SMD) and anxiety (0.71SMD) was large, while it was medium-large for quality of life (−0.58SMD). The association was similar across gender in relation to symptoms of anxiety. For symptoms of depression and quality of life, the association was stronger for girls compared to boys. Our findings yield preliminary evidence of a potential relationship between focus on SOME self-presentation and mental health.