**5. Conclusions**

This study supports the relatively high and stable level of LS in adolescents across the time points investigated, although significant differences in LS scores were found between 2011 and 2016. LS decreased slightly between 13 and 18 years old and increased from 19 and 20 years old. Sex differences in LS were found when controlling for age, but not when controlling for time, stress domains, and self-rated health. All stressors were significantly negatively related to LS, with peer pressure and home life showing the strongest association. Significant interaction effects of sex by interpersonal and schoolrelated stressors in association with LS were found, with stronger associations for girls. The results indicate that stressors affect boys' and girls' LS differently.

**Author Contributions:** Data collection was performed by U.K.M. and G.A.E. Analyses were performed by U.K.M. The first draft of the manuscript was written by U.K.M., and all co- authors G.A.E., S.T.I. and M.L. commented on previous versions of the manuscript. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** The study was conducted in accordance with the Declaration of Helsinki, and approved by the Regional Committee for Medical and Health Research Ethics Mid-Norway (2016/1165, date of approval 04.11.2022).

**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.
