Pestana Pedro Câmara, Cardoso Sandra, Guerreiro Manuela, Maroco João, Jessen Frank, do Couto Frederico Simões, de Mendonça Alexandre
Psychiatry and Mental Health Department, Unidade Local de Saúde de Santa Maria, Av. Prof. Egas Moniz MB, Lisbon, Lisboa, 1649-028, Portugal.
University Clinic of Psychiatry and Medical Psychology, Lisbon Medical School, University of Lisbon, Lisbon, Portugal.
Alzheimers Res Ther. 2024 Dec 5;16(1):261. doi: 10.1186/s13195-024-01634-1.
Subjective Cognitive Decline (SCD) is recognized as a risk stage for future cognitive impairment and dementia. The criteria for SCD include normal performance on neuropsychological testing; however, there is a lack of consensus regarding standard score cut-offs for neuropsychological tests to define cognitive impairment and to differentiate between SCD and Mild Cognitive Impairment (MCI). This study aimed to assess the frequency of SCD diagnosis using various neuropsychological definitions of cognitive normality and to characterize the sociodemographic and neuropsychological features of SCD patients diagnosed under these criteria.
The Cognitive Complaints Cohort (CCC) participants were diagnosed following Subjective Cognitive Decline Initiative (SCD-I) criteria. Normal cognitive performance was defined by the absence of Mild Cognitive Impairment (MCI) according to the five sets of MCI neuropsychologically based criteria defined by Jak and Bondi. Descriptive statistics were used to analyze sociodemographic, clinical, and neuropsychological data. A bootstrap methodology was employed to estimate the mean and 95% confidence intervals (CI) for specific parameters of interest, namely the SMC scale (subjective memory complaints scale), Mini-Mental State Examination (MMSE), Blessed Dementia Rating Scale - first part (BDRS first part), and Geriatric Depression Scale (GDS).
Among the 1268 subjects included, the prevalence of SCD diagnosis exhibited substantial variation across SCD-I criteria using different neuropsychological definitions of cognitive normality (ranging from 16.4 to 81.3%). When using the most conservative criteria to define cognitive impairment (2 tests within a cognitive domain > 1.5 SD below age-adjusted means), the resulting Conservative SCD group had poorer global cognitive function (MMSE: mean 27.15, 95% CI 27.00-27.31), whereas when using the most liberal criteria to define cognitive impairment (only one test > 1 SD below age-adjusted means) the resulting Liberal SCD group had superior performance in daily-life functioning (BDRS first part: mean 0.30, 95% CI 0.23-0.38). However, subjective cognitive complaints and neuropsychiatric symptoms did not significantly differ among SCD diagnostic groups.
The utilization of diagnostic criteria using distinct neuropsychological definitions of cognitive normality significantly impacts the frequency of SCD diagnosis and characterizes different patient populations. Consequently, it is essential to specify the criterion when diagnosing a SCD patient and to understand the risks and benefits of using different criteria to define cognitive impairment.
主观认知下降（SCD）被认为是未来认知障碍和痴呆的一个风险阶段。SCD的标准包括神经心理学测试表现正常；然而，对于用于定义认知障碍以及区分SCD与轻度认知障碍（MCI）的神经心理学测试标准分数临界值，目前尚无共识。本研究旨在评估使用各种认知正常的神经心理学定义进行SCD诊断的频率，并描述在这些标准下被诊断为SCD患者的社会人口学和神经心理学特征。
认知主诉队列（CCC）的参与者按照主观认知下降倡议（SCD-I）标准进行诊断。根据Jak和Bondi定义的五套基于神经心理学的MCI标准，将无轻度认知障碍（MCI）定义为认知表现正常。使用描述性统计分析社会人口学、临床和神经心理学数据。采用自助法估计感兴趣的特定参数的均值和95%置信区间（CI），即主观记忆主诉量表（SMC量表）、简易精神状态检查表（MMSE）、Blessed痴呆评定量表第一部分（BDRS第一部分）和老年抑郁量表（GDS）。
在纳入的1268名受试者中，使用不同的认知正常神经心理学定义，SCD-I标准下SCD诊断的患病率存在显著差异（范围为16.4%至81.3%）。当使用最保守的标准定义认知障碍（认知领域内2项测试低于年龄校正均值1.5个标准差以上）时，由此产生的保守SCD组的整体认知功能较差（MMSE：均值27.15，95%CI 27.00 - 27.31），而当使用最宽松的标准定义认知障碍（仅1项测试低于年龄校正均值1个标准差以上）时，由此产生的宽松SCD组在日常生活功能方面表现更优（BDRS第一部分：均值0.30，95%CI 0.23 - 0.38）。然而，SCD诊断组之间的主观认知主诉和神经精神症状没有显著差异。
使用不同的认知正常神经心理学定义的诊断标准对SCD诊断频率有显著影响，并刻画了不同的患者群体。因此，在诊断SCD患者时明确标准以及了解使用不同标准定义认知障碍的风险和益处至关重要。
