Neurophysiological correlates of excitement in men with recent-onset psychosis.

ABSTRACT

OBJECTIVE: Right frontal function, as indicated by the N200 component of the event-related potential during target detection, has previously been associated with excitement (excitement, impulsivity, hostility, uncooperativeness) in men with a long-term diagnosis of schizophrenia. The current study investigated excitement in relation to N200 in men who had recently experienced their first episode of psychosis. SUBJECTS AND METHODS: Twenty men who had recently suffered their first psychotic episode underwent a clinical interview and auditory oddball task. RESULTS: Multiple linear regression analysis showed that 58% of the variance in the excitement symptom cluster was explained by a positive association with frontal midline N200 amplitude and an inverse association with right frontal N200 amplitude. The latter was not apparent in the initial correlation, suggesting suppression by the midline activity. These associations were not explained by drug use, medication or negative symptoms. However, the correlation between excitement and midline N200 was stronger in drug users, and that between right frontal N200 and excitement was stronger in nonusers. CONCLUSION: Findings support the independent contributions to excitement of mechanisms reflected in midline and right frontal N200 amplitude respectively during the early stages of psychosis.