[Interest of neurophysiological exploration in clinical psychiatry]

Cerebral functional exploration using Event related potentials (ERPs) is greatly relevant in clinical psychiatry. Although ERP usefulness as a diagnostic tool is limited due to the complexity of psychiatric diagnosis, which raises theoretical, methodological and ethical problems that cannot be resolved by neurobiological methods, ERP offers relevant information in 3 different topics: the choice of psychotropes in pharmacotherapy; the description and understanding of cognitive processes; the psychotherapeutic relation. 1) Converging arguments from experimental studies support the hypothesis that the amplitude of P300 and CNV as well as the loudness dependence of the auditory N1/P2 response (LDAEP) are regulated by central catecholaminergic and serotoninergic neurotransmission. These systems also are the target of several psychotropes, and therefore the neurophysiological assessment may bring reliable indicators to predict favourable response to psychotropes and drug intolerance. 2) Moreover the assessment of Reaction Times and P300 and VCN parameters, jointly recorded in a single investigation, brings information about the self-organization and self-regulation of cerebral functioning, and might help the clinicians to understand the functional meaning of attentional disorders in Psychiatry. 3) Finally, the discussion of the neurophysiological results with the patient, in comparing objective and subjective data, might help him to better understand his/her difficulties and to modify his/her subjective experience of the disease.