Cognitive deficit in adults with ADHD lies in the cognitive state disorder rather than the working memory deficit: A functional near-infrared spectroscopy study

Functional Near-Infrared Spectroscopy of English-Speaking Adults With Attention-Deficit/Hyperactivity Disorder During a Verbal Fluency Task

OBJECTIVE

Functional near-infrared spectroscopy (fNIRS) provides direct and quantitative assessment of cortical hemodynamic response. It has been used to identify neurophysiological alterations in medication-naïve adults with attention-deficit/hyperactivity disorder (ADHD). Hence, this study aimed to distinguish both medication-naïve and medicated adults with ADHD from healthy controls (HC).

METHOD

75 HCs, 75 medication-naïve, and 45 medicated patients took part in this study. fNIRS signals during a verbal fluency task (VFT) were acquired using a 52-channel system and relative oxy-hemoglobin changes in the prefrontal cortex were quantified.

RESULTS

Prefrontal cortex hemodynamic response was lower in patients than HCs (p ≤ ≤.001). Medication-naïve and medicated patients did not differ in hemodynamic response or symptom severity (p > .05). fNIRS measurements were not associated with any clinical variables (p > .05). 75.8% patients and 76% HCs were correctly classified using hemodynamic response.

CONCLUSION

fNIRS may be a potential diagnostic tool for adult ADHD. These findings need to be replicated in larger validation studies.

Factors associated with texting and walking performance in children with ADHD: The role of age, environment, and symptom severity

BACKGROUND

Children with ADHD show deficits in executive function, as well as motor symptoms such as difficulties in gross and fine motor skills and gait stability. Texting while walking is becoming increasingly common and is a significant health risk among people of all ages.

RESEARCH QUESTION

The objective of this work was to compare texting and walking performance between children with ADHD and controls and between two environments (indoors and outdoors), and evaluate the role of age and symptom severity in dual-task performance.

METHODS

Nineteen children with ADHD and 30 healthy children walked across an indoors corridor and an outdoors street, with and without texting on a mobile phone. Walking and texting performance were measured using inertial measurement units and a custom-made mobile app.

RESULTS

No between-group differences were found in texting or walking performance. Walking and texting were similar across environments. In both groups, older children had smaller dual-task performance deficits for both gait and texting speed. Children with ADHD who had more severe symptoms of hyperactivity had larger dual task costs for gait speed outdoors (r = 0.69, p = 0.002), and those with more motor symptoms typed faster under dual-task conditions indoors (r = 0.6, p = 0.007) but were less accurate (r = - 0.60, p = 0.009).

SIGNIFICANCE

Children with ADHD do not demonstrate deficits in dual-task performance of a texting and walking task indoors or outdoors. The relationship of age, hyperactivity and motor symptoms with texting and walking performance supports a more personalized approach for examination of dual-task performance in children with ADHD.