Somatosensory function in boys with ADHD and tactile defensiveness.

In this study, we tested for deficits in somatosensory function in boys with Attention Deficit Hyperactivity Disorder (ADHD) and tactile defensiveness (TD). The subjects were 67 boys with ADHD, sub-typed as TD (ADHD+TD+) or non TD (ADHD+TD-), matched with 60 "typical" children in the control group. Sixty nine percent of the boys with ADHD were categorized as TD. The groups were compared on three measures: (a) performance scores on subtests of the Sensory Integration and Praxis Test, (b) measurements of the Somatosensory Evoked Potential (SEP) and (c) ratings of the children's affective responses during tactile stimulation. Both ADHD groups differed from the control group on most study measures. No significant differences were found between the two ADHD subgroups on threshold and perceptual tests scores, except for Finger Identification. However, the TD+ group demonstrated significantly higher central SEP amplitudes than did the TD- group. Together, the results support claims that TD is related to central processing of somatosensory information, but not to anomalous tactile perception, with the exception of Finger Identification.