Contingent Negative Variation and its Relationships to Arousal and Stress in Psychopathology

Abstract

Many attempts to apply Contingent Negative Variation (CNV) in psychiatry have resulted in disappointment because distinctive brain wave patterns have not been found for the major functional psychiatric disorders (Knott and Tecce, 1978; Roth et al., 1984). Indeed, CNV abnormalities were described in patients suffering from several mental disorders (Sartory, 1986; Timsit-Berthier, 1986) but they are not specific to well defined diseases. This lack of specificity is also encountered with other electrophysiological and neurobiological methods such as sleep recording and neuroendocrine challenge tests. In psychiatry, nosological entities have been founded almost exclusively on descriptive clinical criteria. In this respect psychiatry is at variance with other branches of medicine, where diseases are often detected, and sometimes diagnosed entirely using laboratory measures. It is perhaps for such reasons that mental diseases are so heterogeneous with respect to severity, course and drug response. However, it is now beginning to be possible to characterise different subtypes of patients within a nosological category with the help of neurobiological indices. Used in this way, neurobiological indices may be interpreted in the functional trans-nosological manner suggested by Van Praag et al. (1987), who emphasised the psychological dysfunctions instead of the nosological categories. To employ clinical CNV data in this way, it is of importance to specify clearly the kind of information that changes induced by psychopathological conditions are able to provide, and to try to develop, at least in the clinical field, a coherent model of CNV which permits the integration of a large amount of clinical data and the correlation of those data with psychological and/or neurobiological dysfunctions.