Reduced hippocampal volumes feature prominently in schizophrenia patients (SCZ). Although several studies have investigated hippocampal volume alterations between unaffected first-degree relatives (FR) of SCZ and healthy controls (HC), the results were inconsistent. Furthermore, it remains unclear whether FR have specific alterations in hippocampal subfield volumes. Three-Tesla T1-weighted MP-RAGE brain scans were collected from 347 subjects (138 SCZ, 47 FR and 162 HC) and processed using the hippocampal subfields algorithm in FreeSurfer v6.0. We investigated volumetric differences in the twelve hippocampal subfields bilaterally among SCZ, FR and HC. SCZ displayed bilateral reductions in whole hippocampal volume compared with FR and HC. The hippocampal volumes of FR did not differ from those of HC but exceeded those observed in SCZ. We found volumetric differences in specific hippocampal subfields, including the CA1, hippocampal fissure, presubiculum, molecular layer, fimbria and hippocampal-amygdala transitional area, among diagnostic groups. These alterations arose from differences in the hippocampal subfield volumes between SCZ and the other two diagnostic groups. However, right hippocampal fissure volumes linearly increased among the groups. In contrast, no significant volumetric differences were found in other hippocampal subfields between HC and FR. There were no significant intergroup differences in laterality in any hippocampal subfield volumes and no significant correlations between hippocampal subfield volumes and illness duration, psychiatric symptoms, antipsychotics or premorbid IQ in SCZ. Our findings suggest that volumetric alterations in hippocampal subfields (except the hippocampal fissure) in SCZ could be stable phenomena that are present at illness onset and minimally affected by antipsychotics.

减少的海马体积在精神分裂症患者 (SCZ) 中具有显着特征。尽管有几项研究调查了 SCZ 未受影响的一级亲属 (FR) 和健康对照 (HC) 之间的海马体积变化，但结果并不一致。此外，尚不清楚 FR 是否对海马亚区体积有特定的改变。从 347 名受试者（138 名 SCZ、47 名 FR 和 162 名 HC）收集三特斯拉 T1 加权 MP-RAGE 脑部扫描，并使用 FreeSurfer v6.0 中的海马亚区算法进行处理。我们在 SCZ、FR 和 HC 之间双边调查了 12 个海马亚区的体积差异。与 FR 和 HC 相比，SCZ 显示整个海马体积的双侧减少。FR 的海马体积与 HC 的海马体积没有差异，但超过了在 SCZ 中观察到的海马体积。我们发现诊断组之间特定海马亚区的体积差异，包括 CA1、海马裂、前下叶、分子层、菌毛和海马-杏仁核过渡区。这些改变源于 SCZ 和其他两个诊断组之间海马亚区体积的差异。然而，各组间右侧海马裂体积呈线性增加。相比之下，在 HC 和 FR 之间的其他海马亚区中没有发现显着的体积差异。任何海马亚区体积的侧向性均无显着组间差异，并且海马亚区体积与 SCZ 的病程、精神症状、抗精神病药或病前智商之间没有显着相关性。