Recent studies have suggested that a general factor underlies associations among diverse aspects of psychopathology. Newmann et al. (2016) tested the presence and heritability of a general psychopathology factor in parent-, teacher-, and self-reports for 2,115 Dutch 6-8-year-olds participating in the longitudinal Generation R (R = Rotterdam) study. The use of parent-, teacher-, and self-reports is an important strength of the study, because it avoided the possible inflation of associations among problems that may occur when data are obtained from only one source. Parents’ reports were obtained with the CBCL/1½-5, the Social Responsiveness Scale, and the Conners Parent Rating Scale-Revised.
Teachers’ reports were obtained with the TRF. The Berkley Puppet Interview was used to obtain children’s self-reports. Factor analysis yielded a general psychopathology factor on which all scales of all the assessment instruments had significant positive loadings, with the CBCL/1½-5 Aggressive Behavior syndrome having the highest loading. After partialing out variance accounted for by the general psychopathology factor, Neumann et al. found Internalizing and Externalizing factors, with the TRF Withdrawn/Depressed syndrome having the highest loading on the Internalizing factor and the TRF Aggressive Behavior syndrome having the highest loading on the Externalizing factor.
Based on associations of the general psychopathology factor with single nucleotide polymorphism (SNP) alleles, it was estimated that genetic influences accounted for 38% of the variance in the general psychopathology factor. The authors concluded that “Accounting for the interrelated nature of psychiatric disorders may help to unravel part of the complex genetic architecture of child psychopathology” (p. 1044).
Reference: Neumann, A. et al. (2016). Single nucleotide polymorphism heritability of a general psychopathology factor in children. Journal of the American Academy of Child & Adolescent Psychiatry, 55, 1038-1045.