Studies demonstrate that individuals with diagnoses for Major Depressive Disorder (MDD), Post-traumatic Stress Disorder (PTSD), and Schizophrenia (SCZ) may exhibit smaller hippocampal gray matter relative to otherwise healthy controls, although the effect sizes vary in each disorder. Existing work suggests that hippocampal abnormalities in each disorder may be attributable to genetic liability and/or environmental variables. The following study uses baseline data from the Adolescent Brain and Cognitive Development\(^{SM}\) Study (ABCD Study\(\circledR\)) to address three open questions regarding the relationship between genetic risk for each disorder and hippocampal volume reductions: (a) whether polygenic risk scores (PGRS) for MDD, PTSD, and SCZ are related to hippocampal volume; (b) whether PGRS for MDD, PTSD, and SCZ are differentially related to specific hippocampal subregions along the longitudinal axis; and (c) whether the association between PGRS for MDD, PTSD, and SCZ and hippocampal volume is moderated by sex and/or environmental adversity. In short, we did not find associations between PGRS for MDD, PTSD, and SCZ to be significantly related to any hippocampal subregion volumes. Furthermore, neither sex nor enviornmental adversity significantly moderated these associations. Our study provides an important null finding on the relationship genetic risk for MDD, PTSD, and SCZ to measures of hippocampal volume.

研究表明，与其他健康对照者相比，诊断为重度抑郁症 (MDD)、创伤后应激障碍 (PTSD) 和精神分裂症 (SCZ) 的个体可能表现出较小的海马灰质，尽管每种疾病的影响大小各不相同。现有研究表明，每种疾病的海马体异常可能归因于遗传责任和/或环境变量。以下研究使用来自青少年大脑和认知发展\(^{SM}\)研究（ABCD 研究\(\circledR\)) 解决关于每种疾病的遗传风险与海马体积减少之间关系的三个开放性问题：(a) MDD、PTSD 和 SCZ 的多基因风险评分 (PGRS) 是否与海马体积相关；(b) MDD、PTSD 和 SCZ 的 PGRS 是否与沿纵轴的特定海马亚区有差异相关；(c) MDD、PTSD 和 SCZ 的 PGRS 与海马体积之间的关联是否受到性别和/或环境逆境的调节。简而言之，我们没有发现 PGRS 与 MDD、PTSD 和 SCZ 之间的关联与任何海马分区体积显着相关。此外，性别和环境逆境都不会显着缓和这些关联。我们的研究提供了关于 MDD、PTSD、