Co-occurrence of linguistic and behavioural difficulties in early childhood: a developmental psychopathology perspective.

Three hypotheses have been posited as competing explanations for the comorbidity or co-occurrence of language difficulties and behavioural problems among children: (1) language difficulties confer risk for behaviour problems, (2) behaviour problems confer risk for language difficulties, and (3) shared risk factors account for their co-occurrence. We use a developmental psychopathology perspective to propose a model that integrates these explanations, and incorporates several potential moderating, mediating, and shared risk factors. We propose that temperamental negative emotionality and working memory deficits operate to initiate the pathway that may culminate in comorbid language and behaviour problems. We hypothesise that contextual factors (e.g. parent-child interactional processes) and child-specific factors (e.g. adaptive communication) may exacerbate or offset this risk and thus contribute to multiple developmental pathways. The proposed model underscores the importance of considering transactional processes from multiple domains to understand how configurations of risk and protective factors translate into different patterns of children's linguistic and behavioural functioning.