Beyond the Dual Pathway Model: Evidence for the Dissociation of Timing, Inhibitory, and Delay-Related Impairments in Attention-Deficit/Hyperactivity Disorder

Abstract

Objectives: The dual pathway model explains neuro-psychological heterogeneity in Attention Deficit/Hyperactivity Disorder (ADHD) in terms of dissociable cognitive and motivational deficits each affecting some but not other patients. We explore whether deficits in temporal processing might constitute a third dissociable neuropsychological component of ADHD.Method: Nine tasks designed to tap three domains (inhibitory control, delay aversion and temporal processing) were administered to ADHD probands (n=71; ages 6 to 17 years), their siblings (n=71; 65 unaffected by ADHD) and a group of non-ADHD controls (n=50). IQ and working memory were measured. Results:Temporal processing, inhibitory control and delay-related deficits represented independent neuropsychological components. ADHD children differed from controls on all factors. For ADHD patients the co-occurrence of inhibitory, temporal processing and delay-related deficits was no greater than expected by chance with substantial groups of patients showing only one problem. Domain-specific patterns of familial co-segregation provided evidence for the validity of neuropsychological sub-groupings. Conclusion:The current results illustrate the neuropsychological heterogeneity in ADHD and initial support for a triple pathway model. The findings need to replicated in larger samples. preponderance of females controls (gender χ 2 (1) = 9.37, p < .01). Table 1 reports the background and clinical characteristics for the three groups. .

A longitudinal examination of dyadic distress patterns following a skills intervention for carers of adolescents with anorexia nervosa

“…ADHD is also characterized by cognitive difficulties [6], and impacts significantly on management of daily routines [7], school [8], work [9] and social relationships [10]. In addition, ADHD is associated with an increased risk for other neurodevelopmental and psychiatric conditions [11,12], poorer quality of life [13], and premature mortality [14].…”

Domain-general and domain-specific aspects of temporal discounting in children with ADHD and autism spectrum disorders (ASD): A proof of concept study

“…This has been regarded as evidence for a constitutional tendency to prefer immediate over delayed rewards even when the delayed reward is larger, which has been referred to as higher trait time preference in ADHD (Sonuga-Barke & Fairchild, 2012). Other accounts highlight the role of altered emotional reactions to delay ("delay aversion"; Sonuga-Barke et al, 1992;Sonuga-Barke, Bitsakou, & Thompson, 2010) or reduced executive control to inhibit choices for immediate tempting stimuli (Barkley, 1997).…”

Standardised assessment of functioning in ADHD: consensus on the ICF Core Sets for ADHD

“…One possible explanation might be that, since the conceptualisation of ADHD has historically been rooted in a biomedical framework, with its biomedical features already described in ICD-10 [23] and DSM-5 [5], the participating experts may have perceived the development of ICF Core Sets for ADHD as a chance to incorporate personal, social, and environmental aspects of the individual in a more holistic perspective of ADHD [25,43]. Still, however, mental functions were covered in all age-specific brief sets, supporting the notion that ADHD is a persistent neurodevelopmental condition associated with cognitive challenges [44,45]. Notably, motor coordination was included in all core sets, except for the older adolescent and adult version.…”