Language functioning and youth with conduct problems: a meta-analysis

In an effort to better understand conduct problems among children and adolescents, considerable research has focused on the neuropsychological characteristics of youth with such problems. Language, one of several neuropsychological constructs, has been linked to conduct problems in youth. However, there remain many unanswered questions regarding this relationship. Therefore, this study seeks to quantitatively describe the association between conduct problems and language function using meta-analytic procedures. Analyses are guided by the following research questions: What is the magnitude of mean effect size for global language functioning in youth with conduct problems? Do studies evidence a relationship between conduct problems and more specific constructs of language function such as receptive and expressive language? How do certain variables (e.g., age, gender, ethnicity, presence of Attention-Deficit/Hyperactivity Disorder, and type of conduct problem) impact the relationship between conduct problems and language functioning? Relevant articles were identified by keyword searches of the Psych INFO database as well as by examining reference lists of collected articles. This process identified 235 contemporary research articles (i.e. conducted since 1980), which were reviewed for relevant information and subjected to inclusion criteria. Seventeen studies met the following criteria for inclusion: empirical studies conducted since 1980, employing group contrast design with nondisordered controls to investigate language functioning in participants younger than 21-years of age, and utilizing standardized measures of language function. Three separate metaanalyses, one for each language construct, investigated the distribution of standardized mean difference effect size statistics (Hedges's g). Analysis also include d heterogeneity testing and moderator analysis. Results indicated significant effect sizes for global, receptive, and expressive language in the moderate to strong range. Findings also suggested that ethnicity moderates the relationship between language functioning and conduct problems, with minorities at greater risk than non-minorities. Overall, findings provided strong evidence for an underlying neuropsychological deficit in language functioning in many youth with conduct problems, with some demographic variables moderating the magnitude of these effects