The heterogeneity of causes and courses of attention-deficit/hyperactivity disorder

Objective measurement of motor activity during cognitive performance in adults with attention-deficit/hyperactivity disorder

OBJECTIVE

This study investigates whether hyperactivity, i.e. an increased level of motor activity, can be observed in adults with attention-deficit/hyperactivity disorder (ADHD).

METHOD

An infrared motion-tracking system was used to measure motor activity in 20 unmedicated adults with ADHD and 20 matched healthy controls (HC) during a 1-back working memory task.

RESULTS

Motor activity was higher in ADHD. It increased with the duration of testing and co-varied with cognitive performance in ADHD only. Subjective and objective measurements of motor activity were related in HC, but not in ADHD.

CONCLUSION

Higher levels of motor activity in ADHD are objectively measurable not only in children, but in adults as well. It is linked to cognitive performance arguing against distinguishable diagnostic subtypes. The objective measurement of motor activity seems to extend the description of ADHD symptoms derived from rating scales and might thus help to bridge the gap between psychopathological symptom description and neurobiological alterations.

A systematic review of prospective studies on attention problems and academic achievement

OBJECTIVE

Our aim was to provide an overview of prospective studies that have addressed the association between attention problems (AP, i.e. symptoms of hyperactivity and inattentiveness) and academic achievement (AA).

METHOD

We conducted a systematic search in the literature. Normal population studies and clinical studies were included. The methodological quality of each study was evaluated by objective criteria. A best evidence synthesis was used to determine the strengths of the association.

RESULTS

Sixteen studies were included. We found convincing evidence for a negative association between AP and AA. After controlling for intelligence, comorbidity, and socioeconomic status (SES), the association between the hyperactive symptoms of AP and AA was non-significant in two studies.

CONCLUSION

Children with AP are at risk for lower AA and subsequent adverse outcomes later in life. Interventions in affected children should focus on their behavioural and educational development.