Lower GABA levels in Prefrontal Cortex in Individuals at Clinical High Risk for Psychosis who did not remit
Poster B107, Tuesday, October 9, 11:30 am - 1:00 pm, Essex Ballroom
Junjie Wang1, Yingying Tang1, Tianhong Zhang1, Lihua Xu1, Huiru Cui1, Yu Li1, Zhenying Qian1, Yanyan Wei1, Yan Wang1, Xiaochen Tang1, Huan Huang1, Jijun Wang1,2; 1Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai 200030, China, 2CAS Center for Excellence in Brain Science and Intelligence Technology (CEBSIT), Chinese Academy of Science
Objective: We aimed to investigate whether GABA levels in clinic high risk (CHR) for psychosis were associated with subsequent clinical outcome. Method: GABA levels referenced to water were measured in the medial prefrontal cortex (mPFC) with MEGA-PRESS sequence using 3-Tesla proton magnetic resonance spectroscopy in 94 CHR participants and 52 healthy controls, the severity of prodromal psychotic symptoms and cognitive function were assessed with SIPS and MCCB, respectively. Clinical assessment was repeated in 85 CHR subjects at about one-year follow-up. The clinical outcomes of CHR subjects were remission (no longer meeting CHR criteria) and non-remission (still meeting CHR or converting to psychosis). Results: At 1 year follow up, 50 CHR subjects belong to the remission group and 35 belong to the non-remission group. The baseline GABA levels in the mPFC in the non-remission CHR were significantly lower than that in healthy control subjects (non-remission CHR vs. HC: 2.25±0.039 vs. 2.46±0.049, p =0.022), and there was no significant difference between the remission CHR and healthy control subjects (remission CHR vs. HC：2.42±0.05 vs. 2.46±0.049, p =0.10). In addition, baseline mPFC GABA levels were positively correlated to speed of processing performance in MCCB (rho =0.384，p =0.023) within non-remission CHR, which was absent in subjects at remission CHR or healthy controls subjects. Conclusions: An abnormally lower GABA level in the medial prefrontal cortex could suggest a worse prognosis among CHR subjects. The finding supported the key role of GABAergic dysfunction in the pathophysiology of developing psychosis.
Topic Area: Ultra High Risk / Prodromal Research