Seasonal variation in cognitive function and underlying cerebral hemodynamics in humans has been suggested, but not consistently shown in previous studies. We assessed cognitive function in 10,276 participants from the population-based Rotterdam Study, aged 45 years and older without dementia, at baseline and at subsequent visits between 1999 and 2016. Seasonality of five cognitive test scores and of a summary measure of global cognition were determined, as well as of brain perfusion. Using linkage with medical records, we also examined whether a seasonal variation was present in clinical diagnoses of dementia. We found a seasonal variation of global cognition (0.05 standard deviations [95% confidence interval: 0.02–0.08]), the Stroop reading task, the Purdue Pegboard test, and of the delayed world learning test, with the best performance in summer months. In line with these findings, there were fewer dementia diagnoses of dementia in spring and summer than in winter and fall. We found no seasonal variation in brain perfusion. These findings support seasonality of cognition, albeit not explained by brain perfusion.

已经提出了人类认知功能和潜在脑血流动力学的季节性变化，但在以前的研究中并未一致显示。我们评估了 10,276 名来自基于人群的鹿特丹研究的参与者的认知功能，这些参与者年龄在 45 岁及以上，没有痴呆，在 1999 年至 2016 年的基线和随后的访问中。确定了五项认知测试分数的季节性和全球认知的总结测量，以及脑灌注。使用与医疗记录的联系，我们还检查了痴呆临床诊断中是否存在季节性变化。我们发现全球认知的季节性变化（0.05 个标准差 [95% 置信区间：0.02-0.08]）、Stroop 阅读任务、Purdue Pegboard 测试和延迟世界学习测试，夏季表现最佳。根据这些发现，春季和夏季的痴呆诊断比冬季和秋季少。我们发现脑灌注没有季节性变化。这些发现支持认知的季节性，尽管不能用脑灌注来解释。