Psychiatric comorbidity in children and adolescents with reading disability

This study investigated the association between reading disability (RD) and internalizing and externalizing psychopathology in a large community sampl e of twins with (N = 209) and without RD (N = 192). The primary goals were to clarify the relation between RD and comorbid psychopathology, to test fo r gender differences in the behavioral correlates of RD, and to test if com mon familial influences contributed to the association between RD and other disorders. Results indicated that individuals with RD exhibited significan tly higher rates of all internalizing and externalizing disorders than indi viduals without RD. However, logistic regression analyses indicated that RD was not significantly associated with symptoms of aggression, delinquency, oppositional defiant disorder, or conduct disorder after controlling for t he significant relation between RD and ADHD. In contrast, relations between RD and symptoms of anxiety and depression remained significant even after controlling for comorbid ADHD, suggesting that internalizing difficulties m ay be specifically associated with RD. Analyses of gender differences indic ated that the significant relation between RD and internalizing symptoms wa s largely restricted to girls, whereas the association between RD and exter nalizing psychopathology was stronger for buys. Finally, preliminary etiolo gical analyses suggested that common familial factors predispose both proba nds with RD and their non-RD siblings to exhibit externalizing behaviors, w hereas elevations of internalizing symptomatology are restricted to individ uals with RD.