The Covid-19 pandemic brought drastic changes to adolescents’ and families’ lives with implementations of stringent public health measures such as school closures, social distancing protocols and a shift towards more online communications. This thesis focused on mental health among adolescents and families during the Covid-19 pandemic, with specific emphasis on mental distress, eating problems and family dynamics in periods with stringent public health measures. Leveraging rich longitudinal and cross-sectional data gathered before and during the Covid-19 pandemic, this thesis explored environmental and genetic contributions to mental distress and eating problems among adolescents, mothers and fathers.
In the first paper (paper I), 7,781 adolescents responded to questionnaires on mental distress and quarantine over six timepoints between April 2020 and February 2021. A Covid-19 stringency index, measuring the stringency of national public health measures each day in Norway, was matched to the specific dates the adolescents responded to the questionnaires. Paper Ⅰ identified that adolescents reported higher levels of mental distress during periods with more stringent public health measures. Further, adolescents who reported being quarantined in the last two weeks and those who more frequently had experienced quarantine also reported elevated mental distress. We did not identify any specific vulnerable groups of adolescents during periods of more stringent measures and among those who had been recently quarantined. However, the association between being frequently quarantined and mental distress was moderated by selected vulnerability factors. Compared to other quarantined adolescents, being younger, having parents with lower education and having a lower liability to depression were linked to more mental distress after being quarantined frequently.
In the second paper (paper II), 22,706 adolescents responded to a questionnaire including measurements on eating problems. Over a time span of six years, approximately half of the adolescents responded to this questionnaire before the pandemic and the other half, during the pandemic. In paper II, we identified that adolescents who reported during the pandemic experienced more eating problems compared to the adolescents reporting before the pandemic. While both girls and boys displayed elevated symptoms over time, only girls displayed elevated symptoms after adjusting for this general time trend, highlighting a possible pandemic effect. Several personal characteristics and genetic liabilities were associated with eating problems among adolescents such as stress, mental distress, conflict with parents and genetic liability to higher body mass index (BMI) and neuroticism, with some differences among girls and boys. Interestingly, these associations did not differ between adolescents reporting before and those reporting during the pandemic, indicating similar patterns across time. However, some associated behaviors and traits were more frequently reported during the pandemic such as time spent on screen and more mental distress, stress, and conflict with parents – factors that could be part of an explanation for the observed increase in eating problems.
In the third paper (paper III), mental distress was measured over three timepoints among adolescents, mothers and fathers during the first two months of the Covid-19 pandemic (Covid-19 lockdown). This data was linked to genome-wide genetic data resulting in samples of 4,388-27,852 family trios. In paper III, variance explained in mental distress was partitioned into parent-, partner-, or child-driven effects highlighting both individual (direct genetic effects) and family contributions (indirect genetic effects) to mental distress. Our models suggested that indirect genetic explain variance in mental distress of all family members with mother-driven effects contributing to adolescent mental distress, partner-driven effects contributing to mental distress in mothers, and child-driven effects to mental distress in fathers. Mother’s genetic liability to ADHD was also found to be associated with mental distress among fathers. This study also identified direct genetic effects, with genetic liability to depression and neuroticism contributing to mental distress in all family members. In generally, these effects were not moderated by time, although a trend of stronger indirect genetic effects later on in lockdown was observed.
Overall, this doctoral thesis shows that adolescents’ mental distress and eating problems were impacted during the Covid-19 pandemic, shaped by stringent public health measures, family influences and genetic predispositions. The results also point to the importance of family dynamics in influencing mental distress among family members during the Covid-19 lockdown. Knowledge about mental health during the Covid-19 pandemic and possible vulnerable groups are important in guiding research and policies in preparation for future societal crises.