Developmental Language Disorder and Psychopathology: Disentangling Shared Genetic and Environmental Influences

Abstract

There is considerable variability in the extent to which young people with developmental language disorder (DLD) experience mental health difficulties. What drives these individual differences remains unclear. In the current article, data from the Twin Early Development Study were used to investigate the genetic and environmental influences on psychopathology in children and adolescents with DLD ( n = 325) and those without DLD ( n = 865). Trivariate models were fitted to investigate etiological influences on DLD and psychopathology and bivariate heterogeneity and homogeneity models were fitted and compared to investigate quantitative differences in etiological influences on psychopathology between those with and without DLD. The genetic correlation between DLD and internalizing problems in childhood was significant, suggesting that their co-occurrence is due to common genetic influences. Similar, but nonsignificant effects were observed for externalizing problems. In addition, genetic influences on internalizing problems, but not externalizing problems, appeared to be higher in young people with DLD than those without DLD, suggesting that the presence of DLD may exacerbate genetic risk for internalizing problems. These findings indicate that genetic influences on internalizing problems may also confer susceptibility to DLD (or vice versa) and that DLD serves as an additional risk factor for those with a genetic predisposition for internalizing problems.

DLD and Peer Relationships

“…Nearly all the descriptions of the DLD children by participants in this study focused on what could be considered internalizing problems. Although children with DLD may exhibit some externalizing problems such as conduct disorders, aggression, and emotional regulation difficulties, they are more like to exhibit internalizing problems such shyness and social anxiety, particularly by adolescence (Toseeb et al, 2022; van den Bedem et al, 2018). They have fewer peer relationships and they are at greater risk of victimization, social isolation, and depression.…”

Bidirectional associations between mental health problems and language ability across 8 years of childhood

“…Indeed, perinatal complications and preterm birth have been associated with both externalizing symptoms and language di culties [24,25]. Furthermore, internalizing symptoms and externalizing symptoms seem to share genetic etiology [26], and internalizing symptoms and developmental language disorder also have been shown to have shared genetic risk factors [27]. The stability of internalizing symptoms, externalizing symptoms and language ability is in line with previous studies showing that during childhood, the majority of children follow persistent trajectories of no or few internalizing symptoms and no or few externalizing symptoms [2], and a consistent developmental trajectory of language abilities [3] up to adolescence.…”

Low language capacity in childhood: A systematic review of prevalence estimates

“…In the absence of intervention, individuals with a history of low language capacity are at‐risk of poorer academic and vocational outcomes at school‐age (see (Ziegenfusz et al., 2022), adolescence and adulthood (Conti‐Ramsden et al., 2018; Dockrell et al., 2011). Language disorders are also associated with negative psychosocial outcomes in the school‐age years (Beitchman et al., 2001; Maggio et al., 2014), adolescence (Toseeb et al., 2021) and adulthood (Brownlie et al., 2016; Clegg et al., 2005; Whitehouse et al., 2009). Females with language difficulties are at a higher risk of sexual abuse (Brownlie et al., 2007), while males are at an increased risk of engaging in antisocial behaviour (Brownlie et al., 2004).…”