**1. Background**

In today's society, it is acknowledged that assessments of the populations' quality of life (QoL) and subjective wellbeing (SWB) are essential for understanding the welfare of individuals and progress of society [1,2]. This is in addition to measuring welfare aspects such as access to education and work, freedom, and material resources [3,4]. The concept of SWB includes people's appraisals and evaluations of their own lives, including cognitive judgements, such as life satisfaction (LS) and experiences of positive and negative emotions [5,6]. LS represents the cognitive component of SWB and refers to an individual's cognitive, global appraisal of life as a whole [5,7]. Unlike emotional responses, which may fluctuate, overall appraisals of LS have been shown to be a more stable indicator of SWB and for examining adolescents' perceptions of their global life circumstances and functioning [6,7].

Questions about what factors contribute to change and variation in LS have been debated [1]. Adolescence is a distinct period related to understanding variations in LS

**Citation:** Moksnes, U.K.; Innstrand, S.T.; Lazarewicz, M.; Espnes, G.A. The Role of Stress Experience and Demographic Factors for Satisfaction with Life in Norwegian Adolescents: Cross-Sectional Trends over a Ten-Year Period. *IJERPH* **2023**, *20*, 1940. https:// doi.org/10.3390/ijerph20031940

Academic Editors: V. K. Kumar and Jasmin Tahmaseb-McConatha

Received: 28 November 2022 Revised: 16 January 2023 Accepted: 18 January 2023 Published: 20 January 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

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because of the significant changes, transitions, and adaptions in virtually every aspect of an individual's life (physical, social, and psychological). However, studies on LS have mainly been conducted on adults or young adults, with relatively limited research on the adolescent population [5,6]. The transition period from childhood to adulthood now occupies a greater portion of the life course than ever before, due to the earlier onset of puberty, paralleled with the delayed timing of adult responsibilities. The age range between 10 and 19 years has commonly been used to describe the age of adolescence [8]. However, recently, the age range of 10–24 years has been suggested to be more appropriate, reflecting the present understandings of this life phase and is used to define the sample of school students aged 13–20 years old in this study [8]. Consistent with findings reported in studies with adults, most studies with adolescents show that they report high LS, especially in high-income Western countries such as Norway [9]. Regarding trends in self-reports of mental health and wellbeing, an increase in LS was found in a study on the Norwegian adult population from 1984 to 2008, especially for the older age group (40–69 and 70+ years) [1]. A related study based on the same material showed that a significant proportion of the responders had a long-term within-person LS change over the 20-year period [2]. Norwegian studies have shown a strong increase in the prevalence of symptoms of depression and anxiety among young people, especially among adolescent girls [10–12]. A Nordic study (which included Norway) investigating the prevalence of high LS in adolescents aged 11–15 years old between 2002 and 2014 indicated large changes in the prevalence levels at the country level [9]. Norway showed an overall increasing prevalence of high LS over the 12-year period observed, especially in the younges<sup>t</sup> age group [9]. Studies in Western European countries have shown variations in the levels of LS and wellbeing in the younger age groups, showing stability or weak declines in LS and wellbeing over time [13–15]. The relationship between demographic factors (sex, age) and LS seems to be moderately strong [6]. A few studies have shown that LS and wellbeing decrease with age [9,16], whereas other international studies (European, Mexican, and Nordic) have shown that LS seems to be more stable [14,17], or even increases with age, during adolescence [18]. Moreover, girls seem to score lower on LS than boys [8,13,16] and show a larger decline in LS during the adolescent years [9,16].

An individual's perception of LS is regarded as a key indicator of one's overall experience of life circumstances, sensitive to a broad spectrum of functioning [7]. One important factor that may have an impact on LS during adolescence, based on the changes and transitions occurring during this life phase, is the experience of stress. In the present study, stress is defined as a subjective experience of the condition that results when person–environment interactions lead the individual to perceive a discrepancy—whether real or not—between the demands of a situation and the resources available to the person to cope adequately [19]. Stressors signify situations and pressures that cause stress. In addition to major life events that may affect adolescents more randomly, exposure to potential minor chronic or normative everyday stressors (family, peers, and school) increases during the adolescent years and may affect adolescents' ability to cope, consequently affecting wellbeing [14,20–22]. Relevant stressors during adolescence include increasing academic demands, school–leisure conflict, as well as interpersonal stressors including getting along with peers, parents, and romantic relationships [20–22]. In this context, boys seem to experience lower levels of stress than girls [23,24]. Research on the relation between experience of stressors and LS is limited. However, previous research has showed a negative association between LS and stress related to school [20], family [25], and general normative stressors [21,22]. LS has been found to be positively related to a broad spectrum of positive personal, psychological, behavioral, social, interpersonal, and intrapersonal outcomes [5,26]. Although few studies have used the term "stressors" in association with LS, young people's negative evaluations of academic/school variables and interpersonal variables could be perceived as potential stressors in adolescents' lives. Adolescents with higher LS also seem to report more positive psychosocial functioning, compared with those with lower LS [5,6,26].

Adolescence is a particularly important period for understanding levels and trends in LS due to the changes and transitions occurring during this life period, both personally and contextually. A study of changes and transitions may contribute with valuable information to understanding changes in LS [6]. Although the link between stress and health outcomes is well established, few studies have investigated the role of different stressor domains, including school, family, and peers, in association with positive outcomes such as LS. These aspects call for investigating (a) cross-sectional trends in levels of LS, as well as (b) the role of stress domains and socio-demographic differences in association with LS. This study investigated:

