Inhibitory control in children with ADHD

Cure America of Anosognosia

Inhibitory control in children with ADHD

Contributor: Erin Kaseda, Brigham Young University, Neuroscience undergraduate & ANST Member

Overview:  It is estimated that between 5-10% of children and adolescents in the United States have been diagnosed with attention-deficit/hyperactivity disorder (ADHD) [1]. Developmentally appropriate self-regulation allows for social flexibility and goal-oriented motivation; traits often diminished in children with ADHD [2].  Pediatric ADHD populations typically experience attention and academic problems and diminished peer and family relationships.  Parent-child relationships experience increased conflict and poorer parenting practices [3].  Interpersonal difficulties among both peers and family members and academic stress put children with ADHD at risk for comorbid disorders, including depression, anxiety, and oppositional defiant disorder (ODD), and may lead to an increased risk for suicide, the third leading cause of death among adolescents in the United States. 
A wide number of deficits typically associated with ADHD may be a result of poor inhibitory control [4].  Understanding the correlates of inhibitory control in adolescents with ADHD is significant for research and clinical practice on quality of life and improved social and behavioral outcomes.  Go/No-go tasks are valuable in assessing inhibitory control.  In this paradigm, participants are instructed to perform the same motor response for the majority of the task cues, and suppress the go-response to a restricted number of deviant trials (i.e., no-go trials)  [5].  These tasks are widely used to study inhibitory control in various populations and can be used in conjunction with physiological data collection, such as during a functional MRI scan, or can be used alone, offering insight based on response speed and accuracy.
One study examined the default mode network (DMN), comprised of the medial prefrontal cortex and medial and lateral parietal legions, which has been shown to be associated with goal-directed behavior [6]).  In typically developing children, the DMN was significantly deactivated during inhibitory control Go/No-go tasks, regardless of the motivational incentive to perform well at the task.  In subjects with ADHD, DMN activation was high during low-incentive inhibitory control tasks.  However, when those subjects were given a high incentive to perform well at the Go/No-go task, their DMN activation was normalized to the same level as their typically-developing peers[6].  A similar study showed that in a stop signal task, a variation of the go/no-go task, task performance itself was significantly improved in children with ADHD when given a high incentive to perform well, raising their performance level to that of typically developing children [7].  These conclusions offer a potential direction for parents and educators in techniques in improving inhibitory control in adolescents with ADHD.
Interventions that target strengthening inhibitory control during adolescence may decrease the severity of negative behaviors related to inattention and impulsivity.  Incentive-based interventions are beginning to gain attention in public health and education settings.  One study found that monetary incentives resulted in complete abstinence from smoking in 64% of adult smokers with ADHD, a group that smokes at a rate significantly higher than the general population [8].    Another study examined self-imposed incentives on therapeutic assignment completion in college students with ADHD [9].  Further investigation is needed to offer rigorous support for pediatric interventions specifically designed to improve inhibitory control among individuals with ADHD.
Highlighted Abstract:  The problems children with attention-deficit/hyperactivity disorder (ADHD) encounter in tasks measuring inhibitory control are often theoretically related to deficits in cognitive processes. This study investigated the effects of different motivational incentives on the ability of children to inhibit intended or ongoing actions.  In a large German industrial town, 33 children with ADHD were compared with 33 members of a combined group of children with major depressive disorder, anxiety disorders, oppositional defiant disorder, or conduct disorder, and 33 children without any psychiatric disorder with respect to their performances in a stop-signal task. The children received continuous feedback under high-or low-incentive conditions. The children’s performance was compared in terms of qualitative (inhibition rate) and quantitative (reaction time) measures. There were no indications of deficits in sustained attention in children with ADHD. Under conditions of low incentives, children with ADHD were less able to inhibit their reactions and had longer stop-signal reaction times. But when given high incentives, children with ADHD performed the task as well as both other groups. Supposed deficits in children with ADHD should be regarded from a perspective that differentiates performance from ability. Furthermore, the findings support a motivational explanation of the origins of lowered inhibitory control in children with ADHD.
Citation: Slusarek, M., Velling, S., Bunk, D., & Eggers, C. (2001). Motivational effects on inhibitory control in children with ADHD. Journal Of The American Academy Of Child & Adolescent Psychiatry40(3), 355-363.
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[1] Evans, W. N., Morrill, M. S., & Parente S. T. (2010). Measuring inappropriate medical diagnosis and treatment in survey data: The case of ADHD among school-age children.Journal of Health Economics, 29(5), 657-673.
[2] Berger, A., Kofman, O., Livneh, U., & Henik, A. (2007). Multidisciplinary perspectives on attention and the development of self-regulation. Progress in Neurobiology, 82(5), 256-286.
[3] Humphreys, K. L., Katz, S. J., Lee, S. S., Hammen, C., Brennan, P. A., & Najman, J. M. (2013). The association of ADHD and depression: Mediation by peer problems and parent-child difficulties in two complementary samples. Journal of Abnormal Psychology, 122(3), 854-867.
[4] Pliszka, S. R., Liotti, M., & Woldorff, M. G. (2000). Inhibitory control in children with attention-deficit/hyperactivity disorder: Event-related potentials identify the processing component and timing of an impaired right-frontal response-inhibition mechanism.  Biological Psychiatry, 48(3), 238-246.
[5] Uzefovsky, F., Allison, C., Smith, P., & Baron-Cohen, S. (2016). Brief report: The go/no-go task online: Inhibitory control deficits in autism in a large sample. Journal of Autism and Developmental Disorders, 46, 2774-2779.
[6] Liddle, E. B., Hollis, C., Batty, M. J., Groom, M. J., Totman, J. J., …& Liddle, P. F. (2011). Task-related default mode network modulation and inhibitory control in ADHD: Effects of motivation and methylphenidate. Journal of Child Psychology and Psychiatry, 52(7), 761-771.
[7] Slusarek, M., Velling, S., Bunk, D., & Eggers, C. (2001). Motivational effects on inhibitory control in children with ADHD. Journal Of The American Academy Of Child & Adolescent Psychiatry40(3), 355-363.
[8] Kollins, S. H., McClernon, F. J., & Van Voorhees, E. E. (2010). Monetary incentives promote smoking abstinence in adults with attention deficit hyperactivity disorder (ADHD). Experimental and Clinical Psychopharmacology, 18(3), 221-228.
[9] Prevatt, F., Smith, S. M., Diers, S., Marshall, D., Colman, J., … & Miller, N. (2017). ADHD coaching with college students: Exploring the processes involved in motivation and goal completion. Journal of College Student Psychotherapy, 31(2), 93-111.


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