Studying Development of Psychopathology Using Changing Measures to Account for Heterotypic Continuity

Objective: Psychopathology shows changes in behavioral manifestation across development, i.e., heterotypic continuity. However, research has paid little attention to how to account for heterotypic continuity when examining development of psychopathology. This longitudinal study aimed to account for heterotypic continuity of multiple dimensions of psychopathology by using developmental scaling to place ratings by multiple informants of children’s externalizing, internalizing, and thought-disordered problems onto the same scale to chart children’s trajectories.Method: The study examined children’s (N = 231) development of three dimensions of psychopathology—externalizing, internalizing, and thought-disordered psychopathology—using different measures across seven timepoints from 3–7.5 years of age. Psychopathology dimensions were assessed by mother-, father-, and teacher/caregiver-report. We compared three assessment approaches: the common items, upward/downward extension, and construct-valid items approaches. We compared two scoring approaches: mean scoring and developmental scaling. Developmental scaling aims to place scores from different measures onto the same scale. We compared their accuracy in terms of criterion validity with respect to observations of compliance and attention to task.Results: Using different measures across ages (i.e., construct-valid items approach) was the most accurate assessment approach—more accurate than using the common items or upward/downward extension—in terms of criterion validity with respect to observations of compliance and attention to task. Developmental scaling was the most accurate scoring approach.Conclusion: Using (a) changing measures to account for heterotypic continuity and (b) developmental scaling to link the scores from the different measures onto the same scale may enable studying the development of psychopathology across the lifespan.