Event-related potentials are a powerful tool for real-time investigation of the brain’s electrical activity during cognitive processes. There is little data in literature on P 300 evaluation among adolescents suffering from schizophrenia psychosis.

Our goal was to see the relation between the clinical symptoms, improvement of symptoms and medical state on P 300. P 300, were recorded in two adolescent patients - one, with a first episode of psychosis, and another, with long-term diagnosis of schizophrenia. The P 300 wave was evaluated at the begining of the medical treatment and after 8 weeks of medication. We also monitored patient’s clinical state and looked for any improvements on the PANSS.

At the start of the tretman we found a reduced amplitude and a prolonged latency of the P 300 wave. In a follow-up test, a well-formed responses of latency and amplitude, within normal range, were detected in the first case, which coincided with improvements of clinical state and on the PANSS. In the second case, despite an observed clinical improvement and an improvement on the PANSS, the P 300 wave of the patient remained unchanged when compared with the first test.

Our humble results in the context of adolescent schizophrenic psychosis fit in with the fact that the P 300 wave is modulated by changes in positive, but not by changes in negative symptoms or different neuroleptics, which may go to further the claim that the P 300 wave can depend on the clinical state of the patient.