“Possible Medication-Resistant Deficits in Adult ADHD”

Maruta, J., Spielman, L.A., Tseretopoulos, I.D., Hezghia, A., Ghajar, J.

This article reports on neurocognitive and visual tracking performance of adult subjects with ADHD on and off stimulant medication in an effort to clarify the precise attention impairments seen in this population.  Twenty-three adults with ADHD and forty-six two-for-one matched normal controls were assessed on a variety of neurocognitive and visual tracking measures.  Adult ADHD subjects were tested on and off their prescribed stimulant medication, and results of test performance were compared using paired t test statistical analysis.  Tests included the Attention Network Test (ANT), the Spatial Span subtest of the Wechsler Memory Scale, a circular visual tracking test, and a reaction time test.  None of the ANT metrics or visual tracking tests demonstrated differences between controls and ADHD patients on medication.   However, significant differences were seen in the spatial span tests and in the reaction time tests when they were administered after attention-demanding tasks.  These results suggest that for adults with ADHD, stimulant medications can improve visual tracking, reaction time and alerting and orienting, but they do not seem to improve visual-spatial working memory or susceptibility to cognitive fatigue.   These findings are worthwhile considering when advising patients about the benefits of taking stimulant medication insofar as some aspects of cognitive functioning may not improve as dramatically as others do.