A total of 93 patients with panic disorders and 36 healthy control subjects were studied. Clinical-neurological, psychometric, neuropsychological, and neurophysiological (auditory cognitive evoked potentials) investigations were performed. Patients with typical panic disorders were characterized by increased levels of anxiety and depression, along with impairments to cognitive functions in the form of decreases in short-term memory and attention, as compared with healthy subjects. Patients with atypical panic disorders differed from patients with typical panic disorders in having lower levels of anxiety, more severe depression, and more marked cognitive disorders. As compared with healthy subjects, patients with atypical panic disorders showed reductions in the amplitude of the P300 evoked potential wave, while patients with typical panic disorders showed increases. It is suggested that changes in the amplitude parameters of the P300 wave are associated with dysfunction of the limbic-reticular structures of the brain in patients with panic disorders.