On the Spectrum

Chapter 6
ABSTRACT
Background: Psychiatric symptoms in childhood are closely related to neurocognitive deficits.
However, it is unclear whether internalizing and externalizing symptoms are associated with
general or distinct cognitive problems.
Methods: We examined the relation between different types of psychiatric symptoms and
neurocognitive functioning in a population-based sample of 1,177 school-aged children.
Internalizing and externalizing behavior was studied both continuously and categorically. For
continuous, variable-centred analyses, broadband scores of internalizing and externalizing
symptoms were used. However, these measures are strongly correlated, which may prevent
identification of distinct cognitive patterns. To distinguish groups of children with relatively
homogeneous symptom patterns, a latent profile analysis of symptoms at age 6 yielded four
exclusive groups of children: a class of children with predominantly internalizing symptoms,
a class with externalizing symptoms, a class with co-occurring internalizing and externalizing
symptoms, that resembles the CBCL Dysregulation profile and a class with no problems. Five
domains of neurocognitive ability were tested: attention/executive functioning, language,
memory and learning, sensorimotor functioning, and visuospatial processing.
Results: Consistently, these two different modelling approaches demonstrated that children
with internalizing and externalizing symptoms show distinct cognitive profiles. Children
with more externalizing symptoms performed lower in the attention/executive functioning
domain, while children with more internalizing symptoms showed impairment in verbal
fluency and memory. In the most severely affected class of children with internalizing and
externalizing symptoms, we found specific impairment in the sensorimotor domain.
Conclusions: This study illustrates the specific interrelation of internalizing and externalizing
symptoms and cognition in young children.
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