Internalizing and externalizing disorders in childhood and adolescence: A latent transition analysis using ALSPAC data.

BACKGROUND: Research examining the association between internalizing and externalizing dimensions of psychopathology has relied heavily on variable-centered analytical techniques. Person-centered methodologies complement the variable-centered approach, and may help explain the medium-to-large correlations that exist between higher order dimensions of psychopathology. What little person-centered research exists has been cross-sectional and utilized adult samples. The present study sought to take a person-centered approach to the modeling of psychiatric comorbidity during a key developmental phase; middle childhood through adolescence.
METHODS: Analysis was conducted on data from the Avon Longitudinal Study of Parents and Children (ALSPAC, N=9282). Latent transition analysis (LTA) was conducted using eight DSM-IV disorders assessed at ages 7.5 and 14years as measured indicators.
RESULTS: At both time points, a four class solution provided the best fit, with classes labeled as (i) normative, (ii) primarily internalizing, (iii) primarily externalizing, and (iv) high-risk/multimorbid. There was considerable individual-level stability across time, with approximately 80% of children remaining in the same class at both time points. Those in the internalizing class at baseline were more likely to transition to a less severe class (i.e., the normative class).
CONCLUSIONS: Person-centered methodologies demonstrate that the association between internalizing and externalizing is accounted for by a sub-population at high risk for experiencing psychiatric comorbidity, and 'cross-class' disorders which link the internalizing and externalizing spectra.