Sixteen healthy people and 79 patients with panic disorders (PD), including 50 patients with neurosis (ICD-10 F40-41), 18 with personality disorder (F60) and 11 with schizotypal disorder (F21) have been studied. The main investigation method is recording of cognitive evoked potentials (P300 parameters). Mental and neuropsychological status of patients has been assessed as well. Despite the common clinical presentations of PD, peculiarities of evoked potentials reflecting sensory, activation and cognitive processes in different group of patients are revealed. The reduction of activation processes is observed in patients with neurosis and personality disorder combined with emotional instability in the latter ones. The increase of latency in response to non-target stimuli (a sensory component) is shown in schizotypal patients, the latter may be related to the decrease of activation of frontal-central brain areas.