多项研究表明，痴呆症的早期症状可能在确诊前数年就已出现，这些非认知性表现包括晚期抑郁症和焦虑、易激惹或冷漠、睡眠障碍、嗅觉丧失、行走缓慢和握力减弱。[1] 阿尔茨海默病约占痴呆症病例的60-80%，其第一阶段可在任何明显认知变化前开始15-20年。[1] 这些症状由脑部生物学变化引起，往往先于认知功能障碍出现。[1]
情绪变化是最早可被识别的警示信号。2023年丹麦研究表明，被诊断为抑郁症的人患痴呆症的风险是正常人的2.4倍。[1] 2017年的另一项研究发现，约47%有痴呆症风险增加的人出现情绪症状，而认知健康的老年人中仅约31%出现这种情况。[1] 除情绪变化外，感官功能障碍也是重要指标——约85%的早期阿尔茨海默病患者存在嗅觉问题。[1] 身体机能衰退方面，2024年的一项研究在超过1300名65岁以上健康成年人中发现，行走能力下降可能比认知衰退早出现10年。[1] 握力指标同样具有预测意义，握力每下降5公斤，男性患痴呆症风险增加20%，女性增加12%。[1]
预防措施已被证实有效。研究表明约45%的痴呆症病例可通过生活方式改变预防。[1] 美国POINTER临床试验发现，运动、健康饮食、社交互动和脑力游戏可改善老年人的认知能力。[1]
Research indicates that certain non-cognitive symptoms can emerge a decade or more before dementia is formally diagnosed, offering a potential window for early intervention.[1] These warning signs include late-onset depression and anxiety, irritability or apathy, sleep disturbances, loss of smell, slowed walking, and weakened grip strength.[1] According to a 2023 Danish study, people diagnosed with depression face a 2.4 times higher risk of developing dementia compared to those without depression.[1] A 2017 investigation found that approximately 47% of individuals at increased dementia risk experienced mood symptoms, compared with only about 31% of cognitively healthy older adults.[1]
Physical decline may precede cognitive deterioration by a substantial margin.[1] A 2024 study of more than 1,300 healthy adults aged 65 and older demonstrated that reduced walking ability could appear approximately 10 years before cognitive decline becomes apparent.[1] Grip strength also serves as an indicator: for every 5-kilogram decrease in grip strength, men's risk of developing dementia increases by 20% and women's by 12%.[1] Additionally, around 85% of early Alzheimer's disease patients experience olfactory problems.[1] Alzheimer's disease accounts for 60 to 80% of dementia cases, with the initial disease stage potentially beginning 15 to 20 years before any obvious cognitive changes manifest.[1]
The encouraging finding is that approximately 45% of dementia cases may be preventable through lifestyle modifications.[1] The American POINTER clinical trial found that exercise, healthy diet, social engagement, and cognitive activities can improve cognitive function in older adults.[1]