Time to (measure) change: Treatment trajectories of cognitive behavioural intervention effects in adults with Attention Deficit / Hyperactivity Disorder

Abstract

Abstract. Rationale: ADHD is a neurodevelopmental disorder of self-regulation that can persist into adulthood. Carefully designed longitudinal and even meta-analytical studies now inform about its developmental pathways and the underlying neurobiological substrates. Considerably less research efforts have been undertaken to examine the developmental course of changing symptomatic and functional impairments during the intervention period. Despite mainstream interest in the “active ingredients” of cognitive-behavioural interventions, their underlying processes have rarely been addressed until now. Insights into the treatment trajectories are needed and warranted and therefore subject of the present time-series analysis. To the best of our knowledge, this is currently the first time-series analysis of interventional change processes in adult ADHD. Methods: Five patients received a clinical diagnosis of adult ADHD and underwent individual cognitive-behavioural treatment. Treatment provision has been defined as the independent variable and subjected to systematic variations by applying an A-B-A single case design. Symptomatic and functional improvements together with goal attainment and patient satisfaction are the dependent variables. They have been continuously assessed with established measures over a five-week baseline (A) and the entire intervention period (B) as well as during two follow-up measures (A). Visual inspections of treatment trajectories have been undertaken and complemented by the so-called percentage of nonoverlapping data (PND): Nonoverlapping data basically signify discriminative results under treatment compared to baseline conditions and therefore serve as a descriptive effect size measure. Results: All patients except one have attained clinically significant improvements in at least one dependent variable under treatment conditions. Differential outcomes can be discerned from the domain-specific and individual manifestation and magnitude of clinically significant effect sizes: Two clinically significant changes and one promising trend can be observed in symptom severity and goal attainment ratings. Executive relative to psychosocial functioning changes result in slightly higher effect sizes of one clinically significant improvement and two positive trends. Lowest effect sizes have been obtained for improvements in global functioning that seems least responsive to treatment. Discussion: Stepped intervention effects that range from symptom reduction and goal attainment to executive and psychosocial as well as global functioning can be detected. Positive trends tend to follow the module concerned with executive functioning training that qualifies as an “active ingredient.”