DLD, risk factors, and emotional difficulties (St Clair et al., 2019)

Purpose: This study evaluated the pathways between developmental language disorder (DLD), psychosocial risk factors, and the development of emotional difficulties from ages 3 to 11 years within the Millennium Cohort Study.
Method: A total of 14,494 singletons (49.4% female) from the Millennium Cohort Study were evaluated within this study. Risk of DLD (rDLD) was defined as age 5 parent-reported language problems and/or −1.5 SDs on a Naming Vocabulary subtest at the age of 5 years. Children without rDLD formed the general population comparison group. Psychosocial risk factors included 9-month temperamental traits, parental psychological distress, and maternal attachment as well as age 3 emotional regulation abilities, parent–child relationship, and peer problems. The parent report Strengths and Difficulties Questionnaire Emotional Difficulty subscale at 3, 5, 7, and 11 years of age was the outcome variable. The trajectory of emotional difficulties was evaluated within a variable-centered approach and a person-centered approach, using growth mixture modeling.
Results: Children with rDLD (n = 884) had increased levels of emotional problems when compared to the general population group (n = 13,344). Psychosocial risk factors were increased in children with rDLD, fully mediated the increased emotional difficulties at 3 years, and partially mediated the increased emotional difficulties at 11 years. Children with rDLD were more likely to be included in emotional trajectory subgroups with an increasing pattern of emotional problems. rDLD was an additional risk factor for lower levels of emotional self-regulation and increased peer problems when controlling for the emotional difficulties trajectory subgroup.
Conclusion: This article indicates that the increased emotional difficulties found in children with rDLD are likely a function of early language difficulties influencing other domains of development, specifically social interactions (parent and peer) and emotional self-regulation abilities. Clinically, this reiterates the importance of early identification and treatment of children with language delays or clinical level language disorders.

Supplemental Material S1. Further analysis details:
Table S1. Imputation for the mood variable.
Table S2. Correlation between emotional difficulties at age 3, 5, 7, 11 and all predictor variables by rDLD/GP group (general population [GP] in italics with rDLD in normal text).
Table S3. Correlation between emotional difficulties at age 3, 5, 7, 11 and all predictor variables by rDLD Naming Vocabulary and rDLD parent report group (Naming Vocabulary in italics with parent report in normal text).
Table S4. Model fit and sample size information for each growth mixture model evaluated.
Table S5. Full statistics for the rates of demographic, 9 month and 3 year risk factors and emotional symptoms and percentages above cutoff within each subgroup (in comparison to the combined remaining subgroups).
Figure S1. Individual trajectories and subgroup average trajectories for each emotional difficulty trajectory subgroup.

St Clair, M. C., Forrest, C. L., Yew, S. G. K., Gibson, J. L. (2019). Early risk factors and emotional difficulties in children at risk of developmental language disorder: A population cohort study. Journal of Speech, Language, and Hearing Research, 62, 2750–2771. https://doi.org/10.1044/2018_JSLHR-L-18-0061