The aim of this study is to explore the applicability of brain rate (fb) for the diagnosis of attention-deficit/hyperactivity disorder (ADHD), analyzing the spatial distribution of fb through analysis of its values in sagittal and lateral electrodes' positions, recorded in four conditions (eyes closed, eyes opened, visual continuous performance task and emotional continuous performance task).

Sixty-seven adults diagnosed with ADHD according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria and 50 age-matched control subjects participated in the study. The brain activity of the subjects was recorded by 19 channel quantitative electroencephalography (QEEG) system and fb was calculated with the fb software.

Maximum values of fb for sagittal topography are obtained in central region and the minimum in frontal region, while lateral topography maximum values are found in the left and right sides and the minimum in midline region. A positive correlation between the fb values and the QEEG spectra subtypes was obtained, with lower values for normals, first and second subtype, and higher values for the third and fourth subtype. On the other hand, there was no correlation between behavioral symptoms and fb values.

The applicability of an fb indicator in the diagnosis of ADHD is especially pronounced for the higher subtypes (ADHD III and IV), corresponding to heterogeneous and multifactorial character of this disorder.