4.1. Key findings, previous literature, implications
This is the first study, representative of households in Switzerland, that aimed to compare the population-average trajectories of wellbeing between young people and other age groups, spanning the period of 2017–2022. Positive affect and life satisfaction declined among young people (age 14–25) over the entire study period (2017–2022), with the greatest declines before the pandemic, and steeper declines than in other age groups during the entire observation period. Young people experienced a steady decline in satisfaction with life in general, and with leisure activities before and going into-pandemic. Negative affect had been showing a slight increase among young individuals before the pandemic. However, it experienced a slight decline during the initial phase of the pandemic. During the pandemic, negative affect increased and subsequently declined out-of-pandemic. These declines were more modest among young people compared with the oldest groups, not fully compensating for the prior increase. The youngest also reported a greater increase in the feelings of depression and anxiety pre-pandemic (2017–2019) and during the pandemic (2020–2021) as well as an increase in worry pre-pandemic. Hence, wellbeing during the pandemic decreased in all age groups, but the decline has been observed already pre-pandemic among the youngest. In Switzerland, this has also been observed in a consistent rise in admissions to mental health services among young individuals, especially women, starting as early as 2012 [28]. These findings are consistent with studies from other Western European countries. The strength of our study in this context is that, as opposed to most previous studies, we examined changes within the same individuals [12].
Based on the existing knowledge, we can only speculate on the causes behind the decline in wellbeing and mental health among young individuals in Switzerland and other Western European countries, which began several years prior to the pandemic. It is often suggested that young people have become more open about their mental health problems, due to greater mental health awareness [29]. This might imply that wellbeing measures do not consistently capture the same concept over time. However, like others, we found statistical measurement invariance of the wellbeing measure, indicating that the interpratation of the questions remained consistent over time [30]. Another explanation frequently offered in the literature is about the harmful effect of widespread use of social media. However, the evidence that social media may contribute to poorer wellbeing among young people is merely tentative for the time being [31, 32]. Morever, others speculated that the increasingly challenging economic circumstances faced by young individuals (e.g., housing expenses, inflation) might be an important determinant of declining wellbeing. Nevertheless, in Switzerland, economic indicators have remained relatively stable over the past decade (e.g., concerning youth unemployment, youth poverty, or the growth of the gross domestic product; GDP) [33]. This was not entirely the case during the pandemic, as the GDP experienced a decline of 2.4%, and young individuals (< 25 years) were more affected by unemployment compared to other age groups. However, both the GDP and youth employment swiftly rebounded to pre-pandemic levels [33, 34]. Other potential contributors to decreased wellbeing could be the uncertainty that young people face, in terms of precarious employment, climate change and military conflicts. Young individuals might not have developed adequate coping mechanisms to deal with these challenges. This situation could be intensified by constant exposure to a vast amount of information. Indeed, studies during the pandemic have revealed that the rise in time spent on social media platforms was linked to increased symptoms of anxiety and depression.
Also, largely in line with previous international research, wellbeing declined to a greater extent among young people during the pandemic [1–4]. As shown previously, at least in terms of negative affect, after the initial drop, wellbeing started to improve again during the pandemic at the population level [1–4]. Providing a more holistic picture of how well young people did, particularly during the pandemic, across a comprehensive set of indicators can help to speculate about determinants of wellbeing. As a secondary objective, we examined trajectories among young people in other outcomes, related to wellbeing. We found that stress, sleep problems, weakness and weariness all increased pre-pandemic, while the probability of headaches remained stable. Stress, weakness and weariness, and headaches increased during the pandemic, but only stress declined afterwards. The increase in psychosomatic symptoms during the pandemic was documented previously in other countries [35]. Evidence on pre-pandemic trajectories in these indicators is limited. The increase of psychosomatic symptoms during the pandemic may be due to the pandemic constituting a traumatic event (or stressor) [9, 10]. It has been argued that young people may be susceptible to experience trauma, as the pandemic might be the first exposure to severe disease, potential death and grief for many of the young people in high income countries. This is combined with anxiety and worries about infection of themselves, friends and family as well as feelings of uncertainty, and perception of the world as scary and unsafe. Moreover, young people tended to report loneliness, isolation, concerns about education, breakdown of routines as being particularly stressful [5]. Disruption of daily activities and stress related to pandemic might have led to increased family tensions, particularly affecting young people. Young people could also not rely on their social network during the pandemic, due to limited opportunities for socialising with their friends and extended family [36]. Adolescence and young adulthood are critical developmental stages, characterised by transitions across multiple life domains [11]. These transitions could be especially difficult during the pandemic, translating into a greater decline in wellbeing in this age group. However, as shown by multiple studies of both mass trauma and post-traumatic stress disorders most people are resilient in the mid to long term (around 55–85%) [37]. This has also been seen in our study in the trajectory of negative affect, when after the initial increase it bounced back nearly to pre-pandemic levels.
As the second secondary objective, we aimed to identify subgroups who experienced disproportionate changes in wellbeing, stress or psychosomatic symptoms. We did not find any differences according to pre-pandemic characteristics, such as household income, partnership status, being a migrant, or living with parents. The literature on the changes in wellbeing during the pandemic has been largely inconsistent regarding sociodemographic differences [1–4]. However, women, migrants and socioeconomically disadvantaged individuals have often been identified as particularly vulnerable [1–4]. We only found greater increases in negative affect among women and those in neither in education nor employment/training. Those in NEET may have been at a greater risk of being disconnected from opportunities or social networks typically associated with education or employment. Somewhat suprisingly, we did not find any differences according to the household income. One potential explanation is that the protective social welfare policies were largely effective for wellbeing. Likewise, we did not detect any differential changes in wellbeing according to migration or partnerhsip status and whether the pariticipants lived with their parents. This is not to say that absolute differences in wellbeing do not exist between these groups, but rather, they were not exacerbated or reduced by the pandemic.
4.2. Strengths and limitations
The key strength of our study is that it is based on a representative sample of households in Switzerland, followed by two years pre- and post-pandemic. However, as with all longitudinal studies, attrition and nonresponse may have introduced a survival bias to the findings. Those with high wellbeing could be more likely to remain in the study, leading to an underestimation of the drop in wellbeing during the pandemic. We attempted to correct for this bias by retaining those with at least one observation during the entire study period (2017–2022) and using techniques, such as ML and multiple imputation which allow for missing data. However, this still does not correct for the bias due to not contributing any observation at all (e.g., due to attrition prior to 2017).
The second limitation of our study is that we did not have access to a standardised measure of wellbeing. Instead, we derived it using a range of individual items capturing wellbeing. Prior to this study, we found that the measure has robust psychometric properties (e.g., a clear factorial structure, measurement invariance across time and demographic groups). However, the evaluation of effect sizes or comparisons with other studies were somewhat impeded due to the absence of a widely recognized wellbeing measure.