Maartje Boer

SMU AND MENTAL HEALTH 175 6 school achievements, or face-to-face contact with friends one year later, and in turn, changes in these four suggested mediators did not predict changes in SMU problems one year later (Figure 6.3, Appendix Tables A6.1 and A6.2). Thus, in contrast to our expectations, we did not observe any direct or indirect effects of low mental health on SMU problems. Additional Findings Additional Mediations The analyses provided several additional insights. Table 6.3 shows that adolescents whose SMU intensity increased in T1 reported increased SMU problems in T2 (M1a: β = 0.094, p = 0.002), and that in turn, adolescents whose SMU problems increased in T2 showed increased depressive symptoms in T3 (M1a: β = 0.086, p = 0.046) and decreased life satisfaction in T3 (M2a: β = -0.116, p = 0. 017). However, mediation analysis showed that the indirect path between SMU intensity in T1 via SMU problems in T2 to depressive symptoms in T3 was not significant ( β = 0.008, p = 0.093). Also, the indirect path between SMU intensity in T1 via SMU problems in T2 to life satisfaction in T3 was not significant ( β = -0.011, p = 0.060). In addition, increases in SMU intensity in T1 were indirectly associated with increases in upward social comparisons and cybervictimization in T3 via SMU problems in T2 (Figure 6.3). Mediation analyses, however, showed that the strength of these indirect associations was close to zero ( β = 0.015, p = 0.027 and β = 0.014, p = 0.049, respectively). Correlations Within the Same Year The RI-CLPMs also included correlations between (the residuals of the) within-person values of our measures within the same year. The Appendix reports these correlations from M1b to M1e and M2b to M2e (Tables A6.3 and A6.4). Results showed that, although we did not observe any cross-lagged associations between SMU intensity and mental health, adolescents whose SMU intensity increased in T1 reported increased depressive symptoms within the same year (M1b: r = 0.155, p = 0.015). Increases in SMU intensity did not co- occur with decreases in life satisfaction within the same year in any of the waves. Also, adolescents who reported increased SMU intensity in T1 reported increased upward social comparisons (M1b: r = 0.170, p < 0.001), increased