Distinguishing symptom profiles in adolescent ADHD using an objective cognitive test battery

Abstract

Currently diagnosis and assessment of ADHD relies on clinical interview and subjective ratings. Standardized objective cognitive tests can provide additional information about ADHD and help distinguish symptom profiles. Objective: To assess the cognition of adolescent ADHD subtypes using a standardized cognitive test battery. Study Group: Seventy-two ADHD combined subtype, 58 ADHD predominantly inattentive subtype and 130 age-and sex-matched healthy controls. Methods: Cognitive differences between ADHD subtypes were examined according to 1. symptom dimensions (inattentive versus hyperactivity/impulsivity scores) and 2. category (ADHDcom vs. ADHDin). We examined whether cognitive performance would discriminate symptom profiles (from each other and from healthy controls), and whether these profiles could predict test performance. All subjects completed the standardized and fully computerized IntegNeuro test battery using a touch-screen protocol. These tests span the domains of sensori-motor, attention, executive function, language and memory, and have robust construct validity compared to traditional paper-and-pencil tests. The results highlighted the consistency with which performance varied across symptom profiles, irrespective of categorical or dimensional definitions. ADHDcom was primarily distinguished from ADHDin by increased errors and response variability in response inhibition and (to a lesser extent) selective attention tasks. Inattentive symptoms were more likely to predict cognitive performance and there is an indication that despite the same criteria, these symptoms may be more severe in the ADHDcom subtype. Conclusions: These findings highlight the specificity of cognitive deficits, which differentiate ADHD subtypes in adolescence. This study provides consistent evidence that accuracy and response variability in an executive function (response inhibition) task may best distinguish the common ADHD subtypes.

Heterogeneity in ADHD: Neuropsychological Pathways, Comorbidity and Symptom Domains

“…Clarke et al (2007) did conduct such a control in analyses investigating independent as well as interaction effects in the two symptom domains. They found a significant interaction effect for RT variability, showing that it was the combination of high levels of hyperactivity/ impulsivity and inattention that was associated with high RT variability.…”

Development and validation of an attention-deficit/hyperactivity disorder (ADHD) executive function and behavior rating screening battery

“…However, large scale meta-analyses (e.g., Pennington & Ozonoff, 1996;Willcutt, Doyle, Nigg, Faraone, & Pennington, 2005) suggest that ADHD EF deficits extend beyond disinhibition, with planning, working memory, and vigilance skills most consistently Downloaded by [Ams/Girona*barri Lib] at 06:17 03 November 2014 impaired. These EF deficits may reflect a common pathophysiology in the frontal-striatal circuits (Clarke et al, 2007;Hale et al, 2005;Voeller, 2001), at least in CT ADHD, but it remains unclear whether this generalizes to other ADHD subtypes, especially the IT (e.g., Barkley, 1997).…”

“…The CT typically has the greatest EF impairment of the subtypes, especially in response inhibition and motor planning (S. D. Clarke et al, 2007;Houghton et al, 1999;Nigg, Blaskey, Huang-Pollock, & Rappley, 2002). Research on HIT has been limited, but they appear to have better serial ordering, working memory, and visuo-spatial memory and less neuropsychological impairment than other subtypes (Chhabildas, Pennington, & Willcutt, 2001;Weber, Jourdan-Moser, & Halsband, 2007).…”

Reflective and impulsive reactions in ADHD subtypes

“…At the same time our results might indicate that environmental conditions (e.g. quiet home work situation) have a greater effect on children with ADHD-I than on those with ADHD-C. Another explanation of our results may be derived from recent research (Clarke et al 2007) that indicated a greater severity of inattentive symptoms in children with ADHD-C compared to ADHD-I. Other studies Doyle et al 2005) conclude that only a subset of children with ADHD has a deficit in a given neurocognitive mechanism and that a huge variability exists within as well as between subgroups.…”

“…Though the same aspects of cognitive functioning were taken into account in the respective studies, there is no unambiguous support for the differentiation of ADHD subgroups based on these domains. Results of recent studies on cognitive functioning in ADHD subtypes require clarification and replication: despite diagnostic criteria, Clarke et al (2007) found a greater severity on inattentive symptoms in children with ADHD-C compared to those with ADHD-I in their study. Furthermore, a majority of studies on ADHD does not differentiate between subtypes at all or focuses on only one subtype (e.g.…”