How are children's perceptions of the home environment associated with a general psychopathology factor across childhood?

Background: Comorbidity and heterogeneity in psychiatric disorders may stem from a general psychopathology (p) factor influenced by both genetic and environmental factors. Although the relative contributions of these influences on psychopathology are established, the longitudinal associations between p-factor and specific environmental exposures across development are not well understood. Using a longitudinal genetically informative design, this study investigates the association between the home environment and p-factor across childhood. Methods: Data were obtained from the Twins Early Development Study (TEDS). Cross-lagged panel analyses were conducted separately to ascertain the direction of associations between parent-rated p, self-rated p, and self-rated home environment (chaos at home and parental discipline) at ages 9, 12, and 16 (N=6,213). Biometric autoregressive cross-lagged twin models were used to assess the aetiology of these associations, and MZ differences analyses were used to control for familial effects. Results: Both latent factors were stable over time, although twin-rated p-factor (r = 0.44-0.40) was more variable than parent-rated p-factor (r = 0.72-0.63). 'Home environment' was more variable than p-factor uniformly. Small, significant bi-directional associations were found between p-factor and home environment, with stronger cross-lagged paths from p-factor to home environment than vice versa. These longitudinal associations persisted over time, though attenuated for parent-rated p-factor. Genetic analyses revealed that bi-directional cross-lagged paths were largely explained by shared environmental factors, with a smaller proportion explained by genetic factors. This pattern of results was confirmed in MZ differences analyses. Conclusions: Our findings suggest a dynamic and bidirectional relationship between p-factor and the home environment across development, predominantly influenced by shared environmental factors. Changes in one can influence the other, highlighting the complexity of psychopathology's environmental influences. This underscores the need for further investigation into gene-environment interplay to inform approaches to psychopathology prevention and intervention.