Yingying Tang1, Tianhong Zhang1, Junjie Wang1, Lihua Xu1, Zhenying Qian1, Matcheri S. Keshavan2, Susan Whitfield-Gabrieli3, Martha E Shenton4,5, William S. Stone2, Margaret A. Niznikiewicz4, Jijun Wang1; 11. Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 2Beth Israel Deaconess Medical Center, Harvard Medical School, 3McGovern Institute for Brain Research, Massachusetts Institute of Technology, 4Veterans Affairs Boston Healthcare System, 5Brigham and Women's Hospital, Harvard Medical School
Purpose: Mismatch negativity (MMN) indexing pre-attentive sensory processes has been considered a candidate biomarker for predicting transition to psychosis in clinical high risk for psychosis (CHR) individuals. However, in Asian CHR population, the MMN association with psychosis has been less explored. The present study, a part of the Shanghai At-Risk for Psychosis (SHARP) program, examined whether the MMN duration amplitude at baseline can distinguish between remitted non-converters (those who got better) and non-remitted individuals (who included those who converted to psychosis (i.e., converters) and those who remained symptomatic) a year later. Materials and Methods: 104 CHR subjects meeting the Structural Interview for Prodromal Syndromes criteria (Chinese version) and 90 healthy controls (HCs) were tested on the auditory MMN duration paradigm. CHR subjects were grouped into 53 remitted individuals defined as getting clinically better and 51 non-remitted individuals defined as remaining symptomatic, or converting to psychosis, based on their clinical symptoms and functional scores at one-year follow-up. MMN amplitude was analyzed using an ANOVA at midline (Fz, Fcz) with a between-factor of group (remitted CHR, non-remitted CHR and HCs). Results: Group differences were significant (p=0.004) with non-remitted CHR showing less negative MMN amplitude than HC (p=0.0029) and remitted CHR not different from HC (p=0.88) Non-remitters had significantly reduced MMN amplitude relative to remitters (p=0.007). Conclusions: These results suggest that MMN duration amplitude is not only abnormal at baseline in the CHR phase in non-remitters but also distinguishes between CHRs who remitted and those who did not remit one year later.
