Child and parent mental health symptoms in Nigeria: A genetically informed study of pre-school twins in a Low-/Middle-Income Country

BackgroundNinety percent of the world’s children live in Low-/Middle-Income Countries (LMICs),but relatively little is known about children’s mental health risk in these settings. Using agenetically informative twin-family design, we estimated parent-child associations for mentalhealth symptoms (MHSs), indirect effects through specific risk/protective factors, and howparental MHSs impact genetic/environmental influences on child MHSs in Nigeria.MethodsWe recruited 320 twin pairs (aged 3-5 years) and both parents in two Nigerian towns.Participants were assessed for MHSs (emotional/behavioural symptoms in children; anxiety,depressive and Attention-Deficit Hyperactivity Disorder symptoms in parents), and selectedrisk/protective factors (adverse home environments, adverse childhood experiences, poorphysical health; and religiosity, parental warmth and prosociality). We used structural equationmodelling to test parent-child MHS associations, and mediation by risk/protective factors. Weestimated latent genetic (A), shared environmental (C) and individual-specific environmental(E) influences on child MHSs, and how parent MHSs impact these influences using univariatetwin models.ResultsChild MHSs were significantly associated with MHSs in both parents. The strongestindirect effects for parent-child MHS associations were through adverse childhood experiencesand diminished parental warmth. Others indirect pathways involved poor physical health anddiminished prosociality. Latent A and C influences each explained 22-29% of the individualdifferences in children’s MHSs. Independent of A influences, C influences were impacted byparents’ MHSs.ConclusionOur findings indicate that potentially modifiable environmental pathways are importantfor understanding parent-child MHS associations for very young children in a LMIC, and thesemay inform intervention design. Larger and more rigorous genetically informative designs areneeded to replicate and extend our findings.