A hierarchical causal taxonomy of psychopathology across the life span

Abstract

We propose a taxonomy of psychopathology based on patterns of shared causal influences identified in a review of multivariate behavior genetic studies that distinguish genetic and environmental influences that are either common to multiple dimensions of psychopathology or unique to each dimension. At the phenotypic level, first-order dimensions are defined by correlations among symptoms; correlations among first-order dimensions similarly define higher-order domains (e.g., internalizing or externalizing psychopathology). We hypothesize that the robust phenotypic correlations among first-order dimensions reflect a hierarchy of increasingly specific etiologic influences. Some nonspecific etiologic factors increase risk for all first-order dimensions of psychopathology to varying degrees through a general factor of psychopathology. Other nonspecific etiologic factors increase risk only for all first-order dimensions within a more specific higher-order domain. Furthermore, each first-order dimension has its own unique causal influences. Genetic and environmental influences common to family members tend to be nonspecific, whereas environmental influences unique to each individual are more dimension-specific. We posit that these causal influences on psychopathology are moderated by sex and developmental processes. This causal taxonomy also provides a novel framework for understanding the heterogeneity of each first-order dimension: Different persons exhibiting similar symptoms may be influenced by different combinations of etiologic influences from each of the 3 levels of the etiologic hierarchy. Furthermore, we relate the proposed causal taxonomy to transdimensional psychobiological processes, which also impact the heterogeneity of each psychopathology dimension. This causal taxonomy implies the need for changes in strategies for studying the etiology, psychobiology, prevention, and treatment of psychopathology. (PsycINFO Database Record

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Figures

Figure 1

Correlations among first-order latent dimensions of psychopathology identified in a sample of 2,025 pairs of 6–17 year old twins based on adult caretaker reports (A) and youth reports (B) of symptoms. Panel A redrawn from Figure 5 page 196 and panel B redrawn from Figure 7 page 199 (Lahey, Rathouz, et al., 2008). Note: ODD = oppositional defiant disorder; CD = conduct disorder; HI = hyperactivity-impulsivity; INATT = inattention; MDD = major depressive disorder; GAD = generalized anxiety disorder; social = social anxiety disorder; SAD = separation anxiety disorder; spec = specific phobia; agora = agoraphobia.

Figure 2

Best fitting models of the correlational structure of 11 categorical mental disorders in confirmatory factor analyses of diagnosis data from wave 1 of the NESARC sample (A) without a general psychopathology factor, and (B) with a general psychopathology factor. Figure 1, page 973 (Lahey et al., 2012), used by permission.

Figure 3

Variance components from the best-fitting common pathways model from twin analyses of combined parent and youth ratings of 11 dimensions of psychopathology in 9–17 year old children and adolescents in the Tennessee Twin Study (Lahey, Rathouz, et al., 2008) indicating the estimated proportion of phenotypic variance in each of the dimensions explained by shared and dimension-specific additive genetic, shared environmental, and nonshared environmental influences from each higher-order factor. The magnitude each variance component is proportional to the width of the connecting arrow.

Figure 4

Phenotypic correlations of three dispositional constructs measured by the Child and Adolescent Dispositions Scale (Lahey, Applegate, et al., 2008) with latent factors from a bifactor model of the phenotypic correlational structure among 11 first-order dimensions of psychopathology (redrawn from Figure 2, Tackett et al., 2013).

Figure 5

Three-dimensional plots of illustrative parent-reported symptoms of psychopathology of selected disorders based on the mean ratings received by children and adolescents who exhibit the specific symptom on three dispositional constructs measured by the Child and Adolescent Dispositions Scale (Lahey, Applegate, et al., 2008). Neg Emot = negative emotionality.