Study of alterations in P300 evoked potentials in patients with attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is one of the most prevalent developmental problems in school age. Its diagnosis is clinical, through an adequate exploration of symptoms, psychological and performance assessments and the use of specific questionnaires and scales. P300 wave cognitive evoked potentials provide an objective measure that serves as an indicator of the cognitive processes of attention, which is therefore considered an important aid to the diagnosis of these patients.

We studied the P300 wave results obtained through auditory stimuli in 26 pediatric patients: 13 with a recent clinical diagnosis of ADHD and naïve to pharmacological treatment and 13 healthy controls. We measured both the latency and amplitude of the P300 wave, comparing the values in each group, as well as the percentage of errors in the identification of the stimulus in each subject.

We obtained reproducible responses in all study participants, with a mean (SD) latency of 354.25 (41) ms and a mean (SD) amplitude of 11.98 (5.6) µV in the ADHD group compared to 313.59 (21) ms and 13.24 (5.9) µV, respectively, in the control group. There was a higher percentage of errors in the ADHD group. We only found significant differences between groups in the latency of the P300 wave.

Pediatric patients with ADHD exhibited responses with a higher mean latency compared to peers without the disorder, so the assessment of P300 component cognitive evoked potentials could be used as an objective measure to support the diagnosis of ADHD.