External validity of a hierarchical dimensional model of child and adolescent psychopathology: Tests using confirmatory factor analyses and multivariate behavior genetic analyses.

Abstract

Several recent studies of the hierarchical phenotypic structure of psychopathology have identified a General psychopathology factor in addition to the more expected specific Externalizing and Internalizing dimensions in both youth and adult samples and some have found relevant unique external correlates of this General factor. We used data from 1,568 twin pairs (599 MZ & 969 DZ) age 9 to 17 to test hypotheses for the underlying structure of youth psychopathology and the external validity of the higher-order factors. Psychopathology symptoms were assessed via structured interviews of caretakers and youth. We conducted phenotypic analyses of competing structural models using Confirmatory Factor Analysis and used Structural Equation Modeling and multivariate behavior genetic analyses to understand the etiology of the higher-order factors and their external validity. We found that both a General factor and specific Externalizing and Internalizing dimensions are necessary for characterizing youth psychopathology at both the phenotypic and etiologic levels, and that the 3 higher-order factors differed substantially in the magnitudes of their underlying genetic and environmental influences. Phenotypically, the specific Externalizing and Internalizing dimensions were slightly negatively correlated when a General factor was included, which reflected a significant inverse correlation between the nonshared environmental (but not genetic) influences on Internalizing and Externalizing. We estimated heritability of the general factor of psychopathology for the first time. Its moderate heritability suggests that it is not merely an artifact of measurement error but a valid construct. The General, Externalizing, and Internalizing factors differed in their relations with 3 external validity criteria: mother's smoking during pregnancy, parent's harsh discipline, and the youth's association with delinquent peers. Multivariate behavior genetic analyses supported the external validity of the 3 higher-order factors by suggesting that the General, Externalizing, and Internalizing factors were correlated with peer delinquency and parent's harsh discipline for different etiologic reasons. (PsycINFO Database Record

Genetics of attention deficit hyperactivity disorder

“…These studies have shown that a latent shared genetic factor accounts for up to 45% of co-variance across childhood externalizing, internalizing, and phobia symptoms [31,33] and 31% of covariance in childhood neurodevelopmental symptoms [34]. Similar results have been reported for register-based clinical diagnoses, with one study showing that a general genetic factor explained 10-36% of disorder liability across several psychiatric diagnoses [32].…”

Chronic Stress Exposure and Generation Are Related to the P-Factor and Externalizing Specific Psychopathology in Youth

“…This structure has replicated in multiple youth samples (e.g., Castellanos-Ryan et al, 2016; Martel et al, 2017; Neumann et al, 2016; Snyder, Young, & Hankin, 2017; Tackett et al, 2013; Waldman, Poore, van Hulle, Rathouz, & Lahey, 2016). Converging evidence demonstrates the p factor is moderately heritable (Neumann et al, 2016; Waldman et al, 2016), has strong distress-related psychopathology loadings (Waldman et al, 2016) and is associated with negative emotionality (Castellanos-Ryan et al, 2016; Tackett et al, 2013) and poor executive function (Castellanos-Ryan et al, 2016; Huang-Pollock, Shapiro, Galloway-Long, & Weigard, 2016; Martel et al, 2017). Thus, one way to conceptualize the p factor is as shared (partially genetic) liability for psychopathology, characterized by transdiagnostic distress, potentially through the endophenotype of poorly-regulated emotion and cognition (e.g., Beauchaine & Zisner, 2017).…”

“…Importantly, this does not mean that internalizing symptoms are unrelated to chronic stress (see Table 2 showing manifest CDI and MASC correlations with stress), but rather that these associations are likely accounted for by common psychopathology (p factor) rather than relating to specific internalizing variance. Depression and many anxiety disorders (e.g., generalized anxiety) are distress disorders, and distress appears to be mostly captured by the p factor (Waldman et al, 2016). …”

A hierarchical causal taxonomy of psychopathology across the life span.

“…We used a common pathways model in a recent new set of analyses of Tennessee Twin Study data (Waldman, Poore, Van Hulle, Rathouz, & Lahey, in press). Unlike our previous independent pathways modeling of the Tennessee Twin Study data (Lahey et al, 2011), which only examined genetic and nonshared environmental influences, potentially important shared environmental influences on psychopathology (Burt, 2014) also were analyzed using the common pathways model.…”

“…Figure 3 presents a full quantitative description of the hierarchy of causal influences on these 11 first-order dimensions of psychopathology in children and adolescents as revealed in the common pathways model fitted to Tennessee Twins Study data (Waldman et al, in press). The three panels in Figure 3 illustrate the patterns of sharing of each type of causal influence.…”