Executive Functions as Moderators of Response to Behavioral Interventions for Adolescents with Attention-Deficit/Hyperactivity Disorder

EXECUTIVE FUNCTIONS AS MODERATORS OF RESPONSE TO BEHAVIORAL INTERVENTIONS FOR ADOLESCENTS WITH ATTENTION-DEFICIT/HYPERACTIVITY DISORDER By Stephen J. Molitor, M.S. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University. Virginia Commonwealth University, 2019 Major Director: Joshua M. Langberg, Ph.D. Associate Professor Department of Psychology Adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD) experience significant academic impairment and multiple interventions have been developed to address common academic problems, such as difficulties with homework, organization, and planning skills. Given cost and resource constraints, research is needed on factors that mental health providers can use to select the most appropriate interventions. To date, there has been minimal research evaluating moderators of response to ADHD interventions. Further, many of the variables that have been studied do not have strong theoretical ties to the mechanisms of change invoked by the interventions. This study examined potential moderators of treatment response to two academic interventions for adolescents with ADHD: an organizational skills training intervention (HOPS) and a homework completion support intervention (CHIEF). Specifically, the study evaluated whether the cognitive skills known as executive functions (EF) moderate differential treatment response between the interventions. Results indicated that EF abilities were not consistently associated with differential treatment outcomes. Further, significant associations presented conflicting interpretations regarding which profiles of EF abilities were more responsive to HOPS in comparison to CHIEF. Executive Functions as Moderators of Response to Behavioral Interventions for Adolescents with Attention-Deficit/Hyperactivity Disorder Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by life impairment due to persistent difficulties along one or both of two symptom domains: inattention and hyperactivity/impulsivity (American Psychiatric Association, 2013; Biederman, 2005). Symptoms within the inattentive domain include trouble concentrating for extended periods of time, avoiding tasks that require sustained mental effort, and difficulties with organization and planning. Symptoms within the hyperactive/impulsive domain include excessive restlessness, impatience, and excessive talking and interrupting. ADHD is one of the most prevalent mental health disorders found during childhood, with recent estimates indicating that 7-9% of school-age children meet criteria for the disorder (Polanczyk, Willcutt, Salum, Kieling, & Rohde, 2014; Thomas, Sanders, Doust, Beller, & Giasziou, 2015). Although ADHD has a childhood onset, symptoms of ADHD frequently persist through adolescence and into adulthood, with 40% of individuals diagnosed in childhood still experiencing clinically significant symptoms and impairment (Holbrook et al., 2016; Sibley et al., 2017).