The predictive value of P300-amplitudes in the course of schizophrenic disorders.

Auditory P300-amplitudes have been found to be correlated with the social functioning and with the impairment in daily life by negative symptoms in cross-sectional studies. In this prospective longitudinal study, the correlation of auditory P300-amplitudes registrated at the index examination was investigated with the clinical outcome after an average of 2.4 years. Based on previous studies, only schizophrenic patients who were in a stabilized residual state were included in the study. Reference-independent P300-parameters of the index examination were correlated with axis V of DSM-III-R (GAF), with the Brief Psychiatric Rating Scale (BPRS) and with the Scale for Assessment of Negative Symptoms (SANS) assessed at the follow-up examination. The correlation of index P300-amplitude with social functioning at follow-up was significant. No correlations of index P300 with the current symptomatology at follow-up, as expressed by BPRS and SANS was found, however. The results indicate a predictive value of the P300-amplitude on the clinical outcome in terms of social functioning of schizophrenic patients.