Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.
Department of Applied Social Sciences, The Hong Kong Polytechnic University, Hong Kong SAR, China.
J Affect Disord. 2021 Mar 1;282:915-920. doi: 10.1016/j.jad.2020.12.195. Epub 2020 Dec 30.
This study aims to examine if risk of dementia differs between adult- and late-onset depression.
16,608 community-living dementia-free older adults were followed for 6 years to the outcome of incident dementia. Depression was diagnosed according to international diagnostic guidelines. Depression in adulthood or late life was categorized using age 65 as cutoff. Hazard ratio for dementia was estimated using Cox regression analysis.
People with depression in adulthood only did not have higher dementia incidence, suggesting those in remission from adult-onset depression are not at greater risk of dementia. Conversely, having depression in both adulthood and late life was associated with higher dementia risk, and improvement in depression in late life was associated with lower risk, suggesting persistent or recurrent lifetime depression is a risk factor for dementia. Those with depression in late life only were not associated with higher dementia risk after controlling for the longitudinal changes in depressive symptoms, consistent with late-onset depression being a prodrome of dementia.
Reverse causation is a potential limitation. This was minimized by careful ascertainment of depression and dementia cases, exclusion of individuals with suspected dementia at baseline and those who developed dementia within 3 years after baseline, and controlling for various important confounders.
Risk of incident dementia varies with presence and resolution of depression at different ages. Further studies are needed to test whether treating adult-onset depression may prevent dementia. Older adults with a history of depression present for an extended time should be monitored for cognitive decline.
本研究旨在探讨成年期和老年期发病的抑郁症患者发生痴呆的风险是否存在差异。
对 16608 名居住在社区、无痴呆的老年人进行了 6 年的随访，以观察其是否发生痴呆。根据国际诊断标准诊断抑郁症。采用年龄 65 岁作为分界点，将成年期和老年期的抑郁症分为两类。采用 Cox 回归分析估计痴呆的风险比。
仅有成年期抑郁症的患者痴呆发生率没有更高，表明成年期抑郁症缓解后发生痴呆的风险没有增加。相反，同时患有成年期和老年期抑郁症与更高的痴呆风险相关，而老年期抑郁症的改善与较低的风险相关，这表明持续或复发性终生抑郁症是痴呆的一个危险因素。仅患有老年期抑郁症的患者在控制抑郁症状的纵向变化后，与更高的痴呆风险无关，这与老年期发病的抑郁症是痴呆的前驱期相符。
可能存在反向因果关系的局限性。通过仔细确定抑郁症和痴呆病例、排除基线时疑似痴呆的个体和基线后 3 年内发生痴呆的个体，以及控制各种重要混杂因素，尽量减少了这种局限性。
发生痴呆的风险与不同年龄的抑郁发生和缓解情况有关。需要进一步研究以检验治疗成年期抑郁症是否可以预防痴呆。对于有长期抑郁史的老年患者，应监测其认知能力下降情况。
