BACKGROUND Although patients with schizophrenia are well-known to exhibit significant brain volume reduction and cognitive function impairment, it remains unclear as to whether the reduction/impairment is correlated with dopaminergic activity under drug-naïve conditions. METHODS 51 drug-naïve patients with and 128 healthy subjects were recruited in this study. DAT by [99mTc]TRODAT-1 single-photon emission computed tomography (SPECT), regional gray matter volume (GMV) by voxel-based morphometry (VBM) analysis, and cognitive function in terms of IQ were measured in both groups. RESULT A significantly lower DAT availability existed in the drug-naïve group as compared with the healthy subjects (1.67 ± 0.45 vs. 1.98 ± 0.37, P < 0.005). DAT availability was significantly positively correlated with GMV in the left middle frontal lobe (r = 0.58, P < 0.005), the GMV being significantly reduced in the patients with schizophrenia (0.45 ± 0.10 vs. 0.49 ± 0.07, P < 0.005). Furthermore, the GMV in the left middle frontal lobe was significantly and positively correlated with full IQ (r = 0.34, P = 0.02) in the patients with schizophrenia, but not in the controls. CONCLUSIONS Dysregulated dopaminergic activity may modulate volume variation in specific brain areas, and brain volume might alter IQ in drug-naïve patients with schizophrenia.

中文翻译：

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弥合多巴胺、脑容量变异和未用药精神分裂症患者智商之间的关联

背景虽然众所周知，精神分裂症患者表现出显着的脑容量减少和认知功能障碍，但在未使用药物的情况下，这种减少/损害是否与多巴胺能活性相关仍不清楚。方法 本研究招募了 51 名未接受药物治疗的患者和 128 名健康受试者。[99mTc]TRODAT-1 单光子发射计算机断层扫描 (SPECT) 的 DAT、基于体素的形态测量 (VBM) 分析的区域灰质体积 (GMV) 和 IQ 方面的认知功能在两组中进行了测量。结果 与健康受试者相比，未使用药物组中存在显着较低的 DAT 可用性（1.67 ± 0.45 与 1.98 ± 0.37，P < 0.005）。DAT 可用性与左中额叶 GMV 显着正相关（r = 0.58，P < 0.005），精神分裂症患者的 GMV 显着降低（0.45 ± 0.10 vs. 0.49 ± 0.07，P < 0.005）。此外，精神分裂症患者左中额叶的 GMV 与全智商显着正相关（r = 0.34，P = 0.02），但在对照组中则不然。结论 失调的多巴胺能活动可能会调节特定脑区的容量变化，而脑容量可能会改变未接受药物治疗的精神分裂症患者的智商。