Data_Sheet_1_Obsessive-Compulsive Symptoms, Polygenic Risk Score, and Thalamic Development in Children From the Brazilian High-Risk Cohort for Mental Conditions (BHRCS).docx

Background: Thalamic volume measures have been linked to obsessive-compulsive disorder (OCD) in children and adolescents. However, it is unclear if alterations in thalamic volumes occur before or after symptom onset and if there is a relation to the presence of sub-clinical obsessive-compulsive symptoms (OCS). Here, we explore the relationship between OCS and the rate of thalamic volume change in a cohort of children and youth at high risk to develop a mental disorder. A secondary aim was to determine if there is a relationship between OCS and the individual's OCD polygenic risk score (OCD-PRS) and between the rate of thalamic volume change and the OCD-PRS.
Methods: The sample included 378 children enrolled in the longitudinal Brazilian High-Risk Cohort for Mental Conditions. Participants were assessed for OCS and the symmetrized percent change (SPC) of thalamic volume across two time-points separated by 3 years, along with the OCD-PRS. Zero-altered negative binomial models were used to analyze the relationship between OCS and thalamic SPC. Multiple linear regressions were used to examine the relationship between thalamic SPC and OCD-PRS.
Results: A significant relationship between OCS and the right thalamus SPC (p = 0.042) was found. There was no significant relationship between changes in thalamic volume SPC and OCD-PRS.
Conclusions: The findings suggest that changes in the right thalamic volume over the course of 3 years in children may be associated to OCS. Future studies are needed to confirm these results and further characterize the specific nature of OCS symptoms associated with thalamic volumes.

研究背景：丘脑体积测量指标已被证实与儿童及青少年的强迫症（Obsessive-Compulsive Disorder, OCD）相关。然而目前尚不清楚丘脑体积的改变是出现于症状发作前还是发作后，也不清楚其与亚临床强迫症状（sub-clinical obsessive-compulsive symptoms, OCS）的存在是否存在关联。本研究旨在探讨在罹患精神障碍高风险的儿童与青少年队列中，OCS与丘脑体积变化速率之间的关联。本研究的次要目标为明确OCS与个体的强迫症多基因风险评分（OCD polygenic risk score, OCD-PRS）之间，以及丘脑体积变化速率与OCD-PRS之间是否存在关联。

研究方法：本研究纳入378名来自巴西精神疾病高风险纵向队列（Brazilian High-Risk Cohort for Mental Conditions）的儿童作为研究对象。研究人员对参与者进行了OCS评估，并测量了间隔3年的两个时间点下的丘脑体积对称化百分比变化量（symmetrized percent change, SPC），同时采集了其OCD-PRS数据。本研究采用零调整负二项模型（Zero-altered negative binomial models）分析OCS与丘脑体积SPC之间的关联；采用多元线性回归分析丘脑体积SPC与OCD-PRS之间的关联。

研究结果：本研究发现OCS与右侧丘脑体积SPC之间存在显著关联（p=0.042）。丘脑体积SPC变化与OCD-PRS之间未发现显著关联。

研究结论：本研究结果提示，儿童群体中3年间的右侧丘脑体积变化可能与OCS相关。未来仍需开展相关研究以验证本研究结果，并进一步明确与丘脑体积相关的OCS症状的具体特征。