Intra-familial dynamics of mental distress during the Covid-19 lockdown

ImportanceLockdowns and social restrictions imposed in response to the Covid-19 pandemic intensified the proximity and reciprocal exposure among members of nuclear families. It is unclear how variation in mental distress during this period is attributed to family members influence. ObjectiveUsing genetic data from family members, it is possible to disentangle parent-driven, child-driven, and partner-driven influences of mental distress. We separated between two types of influences; direct genetic-how an individuals genotype influences their own mental distress, and indirect genetic-how an individuals genotype influence the mental distress of family members. Design, Setting and ParticipantsBased on a pre-registered analysis plan, we used longitudinal data from the Norwegian Mother, Father and Child Cohort Study, reported by adolescents (N=4,388), mothers (N=27,852) and fathers (N=25,953) during the first two months of the Covid-19 lockdown. Trio genome-wide complex trait analyses were used to separate direct and indirect genetic effects at each timepoint. Separate models also included adolescents non- pandemic responses (N=10,012). Trio polygenic score (PGS) design was used to investigate direct and indirect effects of specific liability factors, and whether the associations changed over days in lockdown, adding interaction terms (PGSxtime). ExposureFamily trios genotype and PGS for anxiety, depression, ADHD, neuroticism, and anorexia nervosa. Main OutcomeMental distress was measured using the five-item version of the Hopkins Symptom Checklist. ResultsWe found evidence of family members influencing each other, with a pattern of greater proportions of variance explained later in lockdown. Indirect genetic effects were observed across family members; 10% of the variance in adolescent mental distress was mother-driven, 2-3% in mothers were partner-driven, and 5% in fathers were offspring-driven. Mothers genetic liability to depression and ADHD was positively associated with fathers mental distress. No interaction effects between PGS and time were found. Direct genetic effects contributed to 9-10% variance in mental distress across family members, partly explained by genetic variants associated with anxiety, depression, ADHD, and neuroticism. Conclusions and RelevanceThese findings highlight the importance of family dynamics, particularly during societal crises like the Covid-19 pandemic and emphasizes the value of including family members in mental health interventions. Key PointsO_ST_ABSQuestionC_ST_ABSHow did mothers, fathers and adolescent offspring influence each others mental distress during the Covid-19 lockdown? FindingsUp to 10% of the variance in mental distress was explained by family-related environmental factors (proxied by genetic variants in family members). Mother-driven effects were most important among adolescents, while father-driven effects explained variance among mothers, and child-driven effects explained variance in fathers. Fathers mental distress was also higher when mothers had higher genetic liability for ADHD and depression. MeaningThe findings highlight the potential value of including family members in mental health interventions.