Neurophysiological correlates of excitement in schizophrenia.

OBJECTIVE

The excitement cluster (excitement, hostility, uncooperativeness and impulsivity) may contribute to the risk of violent behaviour, treatment non-adherence, likelihood of discharge and substance use in psychosis. Evidence suggests involvement of frontal executive mechanisms that may show sex differences in their association with symptom severity. The current study tests the association between excitement and the frontal N200 and P300 components of the auditory event-related potential in schizophrenia as a function of sex.

METHOD: Fourteen men and 14 women with schizophrenia (mean illness duration=20years) completed a novelty oddball and clinical interview.

RESULTS

Men showed higher midline N200 and lower novelty P300 amplitude than women. They had more pronounced differences between midline and lateral N200 amplitude, and did not show the same Novel>Target effect for right frontal P300 as did women. Right frontal N200 amplitude to target stimuli was positively associated with excitement in women and inversely associated with excitement in men. Novelty P300 amplitude was inversely associated with excitement, particularly in women and over the right hemisphere.

CONCLUSION

Results suggest that mechanisms underpinning frontal N200 and P300 subcomponents are differentially involved in excitement depending on sex. Understanding these individual differences may have implications for developing personalised treatment.