Intensity dependence of auditory evoked potentials (IDAP) in adult attention deficit/hyperactivity (ADHD) disorder.

Intensity-dependent auditory evoked potentials (IDAP) were shown to be increased in highly impulsive individuals. As impulsivity is one of the core symptoms of attention deficit/hyperactivity disorder (ADHD), patients with ADHD were expected to exhibit an enhanced IDAP. Twenty-five ADHD patients taking methylphenidate and 21 healthy control participants were given diagnostic questionnaires including the Barratt Impulsivity Scale and IDAP was assessed with five-tone intensities. Amplitude, latency, and intensity slope of the N1, P2, and N1/P2 were determined. Contrary to our hypothesis, there was no significant group difference with regard to N1 amplitude and ADHD patients exhibited significantly lower P2 amplitude at high intensity and a flatter N1/P2 slope of the stimulus intensity function than healthy controls. Motor impulsivity, a subscale of the Barratt impulsivity scale, showed a significantly negative correlation with P2 amplitude within the ADHD group. The unexpected results could be due to the effect of methylphenidate. (PsycINFO Database Record (c) 2014 APA, all rights reserved)
Source: Journal of Psychophysiology - Category: Psychiatry & Psychology Authors: Source Type: research