Cognitive Deficits and Clinical Symptoms with Hippocampal Subfields in First-Episode and Never-Treated Patients with Schizophrenia

Memory dysfunction and associated hippocampal disturbances play crucial roles in cognitive impairment of schizophrenia. To examine the relationships between cognitive function and the hippocampal subfields (HSs) in first-episode never-treated (FENT) schizophrenia patients, the HSs were segmented in 39 FENT patients and 30 healthy controls using a state-of the-art automated algorithm. We found no significant differences in any HSs between the patients and controls. However, multivariate regression analysis showed that the left cornu ammonis 1 (CA1), left hippocampal tail, left presubiculum, and right molecular layer contributed 40% to the variance of the PANSS negative symptom score. After adjusting for sex, age, education, and intracranial volume, the partial correlation analysis showed that the volumes of left CA1, CA3, CA4, molecular layer, granule cell layer and both left and right subiculum were negatively correlated with the MATRICS consensus cognitive battery (MCCB) Hopkins Verbal Learning Test (HVLT). Multiple regression analysis showed that the left CA1 and CA3 hippocampal abnormalities contributed 66% to the variance of the HVLT. Our results suggest no detectable HS deficits were found in FENT schizophrenia patients. However, the HSs may be involved in the symptoms and cognitive deficits of schizophrenia patients in the early phase of their illness.