Reduced mismatch negativity predates the onset of psychosis

The MMN amplitude was significantly reduced in the ARMS group compared to controls. Of the at-risk subjects who completed followed up (n = 41), ten (24% of baseline sample) subsequently developed psychosis. The MMN amplitude in this subgroup was significantly smaller across all three recording sites (FZ, F3 and F4) than in the ARMS individuals who did not become psychotic. Conclusion: Among those with the ARMS, MMN amplitude reduction is associated with an increased likelihood of developing frank psychosis.