Sunah Choi1, Minah Kim2, Hyungyou Park1, Taekwan Kim3, Sun-Young Moon2, Silvia Kyungjin Lho2, Junhee Lee2, Jun Soo Kwon4. 1. Department of Brain and Cognitive Sciences, Seoul National University College of Natural Sciences, Seoul, Republic of Korea. 2. Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea; Department of Psychiatry, Seoul National University College of Medicine, Seoul, Republic of Korea. 3. Department of Brain and Cognitive Sciences, Seoul National University College of Natural Sciences, Seoul, Republic of Korea; Department of Bio and Brain Engineering, Information & Electronics Research Institute, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea. 4. Department of Brain and Cognitive Sciences, Seoul National University College of Natural Sciences, Seoul, Republic of Korea; Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea; Department of Psychiatry, Seoul National University College of Medicine, Seoul, Republic of Korea; Institute of Human Behavioral Medicine, SNU-MRC, Seoul, Republic of Korea. Electronic address: kwonjs@snu.ac.kr.
Abstract
BACKGROUND: Hippocampal volume changes have been reported in schizophrenia patients and their relatives and are proposed to contribute to the pathophysiology of schizophrenia. However, volume changes in the total hippocampus have not been consistently reported in relatives. The hippocampus consists of multiple subregions, and based on previous inconsistent results, subtle changes in specific subregions may occur in relatives. Here, we examined the subregion volumes in unaffected, high-functioning relatives (URs) without any psychiatric symptoms with high genetic loading with at least one first-degree relative diagnosed with schizophrenia and at least one or more other affected first- to third-degree relatives. METHODS: We acquired structural magnetic resonance imaging data from 50 URs, 101 first-episode psychosis (FEP) patients, and 101 healthy controls (HCs). The cornu ammonis (CA), dentate gyrus, and subiculum subfields were automatically segmented using FreeSurfer 7.1.0. Each subregion volume was compared across the groups. RESULTS: Compared with the HCs, the URs had a significant volume reduction in the left anterior CA (p = 0.039, Cohen's d = 0.480). In addition, the URs had a significantly larger right posterior subiculum (p = 0.001, Cohen's d = 0.541) than the FEP. CONCLUSIONS: The smaller left anterior CA in the URs may reflect their genetic vulnerability to schizophrenia and supports previous findings suggesting specific vulnerability in this region. The volume differences between the URs and FEP patients in the right posterior subiculum may suggest that a smaller volume in this region may reflect a risk for schizophrenia other than genetic vulnerability.
BACKGROUND: Hippocampal volume changes have been reported in schizophrenia patients and their relatives and are proposed to contribute to the pathophysiology of schizophrenia. However, volume changes in the total hippocampus have not been consistently reported in relatives. The hippocampus consists of multiple subregions, and based on previous inconsistent results, subtle changes in specific subregions may occur in relatives. Here, we examined the subregion volumes in unaffected, high-functioning relatives (URs) without any psychiatric symptoms with high genetic loading with at least one first-degree relative diagnosed with schizophrenia and at least one or more other affected first- to third-degree relatives. METHODS: We acquired structural magnetic resonance imaging data from 50 URs, 101 first-episode psychosis (FEP) patients, and 101 healthy controls (HCs). The cornu ammonis (CA), dentate gyrus, and subiculum subfields were automatically segmented using FreeSurfer 7.1.0. Each subregion volume was compared across the groups. RESULTS: Compared with the HCs, the URs had a significant volume reduction in the left anterior CA (p = 0.039, Cohen's d = 0.480). In addition, the URs had a significantly larger right posterior subiculum (p = 0.001, Cohen's d = 0.541) than the FEP. CONCLUSIONS: The smaller left anterior CA in the URs may reflect their genetic vulnerability to schizophrenia and supports previous findings suggesting specific vulnerability in this region. The volume differences between the URs and FEP patients in the right posterior subiculum may suggest that a smaller volume in this region may reflect a risk for schizophrenia other than genetic vulnerability.