Temperament, executive function, and attention-deficit/hyperactivity disorder (ADHD) in adolescents: The mediating...

Introduction: Temperament dimensions may be related to executive functions (EF) and may be involved in the expression and maintenance of symptoms of attention-deficit/hyperactivity disorder (ADHD). The current study aimed to assess whether effortful control (EC) mediates the relationship between EF and inattentive symptoms, and whether surgency (S) and negative affectivity (NA) mediate the relationships between EF and hyperactive-impulsive ADHD symptoms in adolescents. Method: Working individually, participants aged between 12 and 16 years (N = 118; 75 with ADHD) performed tests of cognitive EF (working memory, planning, flexibility, and inhibition), and parents and teachers completed a multi-informant assessment focusing on measures of ADHD symptoms and temperament dimensions (EC, S, and NA). Results: There were significant differences between ADHD and control participants in EF and temperament dimensions. ADHD participants had lower scores than controls in working memory, planning, and inhibition EF; they also had lower scores in EC and higher scores in S and NA. Structural equation modeling indicated differential associations between EC, S, and NA temperament dimensions, and working memory, planning and inhibition EF, and ADHD symptoms. Mediation analysis suggested that EF exerted indirect effects on the inattentive and hyperactive-impulsive symptoms, via EC; higher EF abilities were related to higher levels of EC, which in turn were related to lower scores of inattentive and hyperactive-impulsive ADHD symptoms. S and NA did not mediate relations among EF and hyperactive-impulsive symptoms. Conclusion: The findings expand on those of previous studies of the complex relationship between temperament dimensions and EF and confirm the differential association between impairments in some EF, low EC, and the expression of inattentive and hyperactive-impulsive symptoms in adolescents, which may account for the ADHD-control group differences.