Developmental co-occurrence of psychopathology dimensions in childhood

Abstract

BackgroundComorbidity between psychopathologies may be attributed to genetic and environmentaldifferences between people as well as causal processes within individuals, where onepathology increases risk for another. Disentangling between-person (co)variance fromwithin-person processes of psychopathology dimensions across childhood could shed light ondevelopmental causes of comorbid mental health problems. Cross-sectional data as well asstandard models to investigate lagged effects conflate between-person and within-personprocesses. This makes it difficult to distinguish time invariant overarching (confounding)factors from temporal directed effects. Additionally, more recent random effects modelsmake no allowance for direct temporal effects from one person to another. Here, we aim todetermine whether and to what extent directional relationships between psychopathologydimensions within-person, and between individuals within families, play a role inmultivariate comorbidity.MethodsWe investigated longitudinal data on measures of common psychopathologies fromchildhood to early adolescence (age 7 to 12), jointly estimating between-person and withinpersonprocesses across time. We conducted random intercepts cross-lagged panel model(RI-CLPM) analyses to unravel the longitudinal co-occurrence of child psychopathologydimensions, and developed an extension of the model to estimate sibling effects withinfamily(wfRI-CLPM). Analyses were separately conducted in two large population-basedcohorts, the Twin Early Developmental Study and the Netherlands Twin Register, includingparent-rated measures of child problem behaviours based on the SDQ and CBCL scalesrespectively.ResultsWe found evidence for strong between-person effects underlying the positive intercorrelationbetween problem behaviours across time. We further identified time-varying within-personprocesses accounting for an increasing amount of trait variance overtime, up to 11% forattention problems in TEDS, and up to 18% for attention problems and social problems inNTR. Lastly, by accommodating family-level data, we found evidence for reciprocaldirectional influences within sib-pairs longitudinally, from externalizing to internalizingproblems, after accounting for similarities that arise through shared (genetic orenvironmental) influences.Co-occurrence of psychopathology dimensions in childhoodConclusionsOur results indicate that within-person processes partly explain the co-occurrence ofpsychopathology dimensions in childhood, and within families, suggesting that both shouldbe taken into account in developmental models of comorbidity.

One mental health problem influencing the risk for another, within individuals and between siblings. Commentary on Allegrini et al. (2022)

“…Allegrini et al. (2022) have taken a rather novel approach in exploring mechanisms underlying co‐occurrence of symptoms over time. Focusing on social, internalising, attention deficit hyperactivity disorder (ADHD) and externalising symptoms, they not only included between person processes in their longitudinal model, like in the before mentioned studies, but also within person processes to explain the co‐occurrence of symptoms.…”