Age of Alzheimer's disease diagnosis in people with Down syndrome and associated factors: Results from the Horizon 21 European Down syndrome consortium.

INTRODUCTION: People with Down syndrome (DS) have high risk of developing Alzheimer's disease (AD). This study examined mean ages of AD diagnosis and associations with co-occurring conditions among adults with DS from five European countries. METHODS: Data from 1335 people with DS from the Horizon 21 European DS Consortium were used for the analysis. RESULTS: Mean ages of AD diagnosis ranged between 51.4 (SD 7.0) years (United Kingdom) and 55.6 (SD 6.8) years (France). Sleep-related and mental health problems were associated with earlier age of AD diagnosis. The higher number of co-occurring conditions the more likely the person with DS is diagnosed with AD at an earlier age. DISCUSSION: Mean age of AD diagnosis in DS was relatively consistent across countries. However, co-occurring conditions varied and impacted on age of diagnosis, suggesting that improvements can be made in diagnosing and managing these conditions to delay onset of AD in DS. HIGHLIGHTS: Mean age of AD diagnosis was relatively consistent between countries Sleep problems and mental health problems were associated with earlier age of AD diagnosis APOE ε4 carriers were diagnosed with AD at an earlier age compared to non-carriers Number of co-occurring conditions was associated with earlier age of AD diagnosis No differences between level of intellectual disability and mean age of AD diagnosis.

The French translation of the dementia screening questionnaire for individuals with intellectual disabilities is a sensitive tool for screening for dementia in people with Down Syndrome.

BACKGROUND: People with Down Syndrome (DS) are at an increased risk of developing Alzheimer's Disease (AD) relatively early in life. The dementia screening questionnaire for individuals with intellectual disabilities (DSQIID) has been developed for people with intellectual disabilities and was shown to have high discriminative power to distinguish between people with and without dementia. The objective of this study was to verify if the French version of the DSQIID (DSQIID-F) had a good diagnostic specificity and to determine the optimal cut-off for screening people with DS for dementia. METHOD: This was a single-centre, retrospective, medical chart review study in people with DS aged ≥40 years. Demographics, level of intellectual disability, DSQIID-F data and clinical assessment of dementia were extracted from medical records. Sensitivity and specificity for different DSQIID-F cut-offs were calculated to determine the optimal cut-off. RESULTS: 151 people with DS were included with a median age of 51 years. The optimal DSQIID-F cut-off was 19, sensitivity was 0.940 (95 % CI: 0.830; 0.985) and specificity was 0.941 (95 % CI: 0.873; 0.975). Results were comparable to those for the English DSQIID (cut-off: 20; sensitivity: 0.92; specificity: 0.97). However, the psychometric qualities of the DSQIID-F, used for clinical follow-up, have not been verified. CONCLUSIONS: The DSQIID-F has good discriminative power and represents a useful tool to screen people with DS for dementia.

The Behavioral and Psychological Symptoms of Dementia in Down Syndrome Scale (BPSD-DS II): Optimization and Further Validation.

BACKGROUND: People with Down syndrome (DS) are at high risk to develop Alzheimer's disease dementia (AD). Behavioral and psychological symptoms of dementia (BPSD) are common and may also serve as early signals for dementia. However, comprehensive evaluation scales for BPSD, adapted to DS, are lacking. Therefore, we previously developed the BPSD-DS scale to identify behavioral changes between the last six months and pre-existing life-long characteristic behavior. OBJECTIVE: To optimize and further study the scale (discriminative ability and reliability) in a large representative DS study population. METHODS: Optimization was based on item irrelevance and clinical experiences obtained in the initial study. Using the shortened and refined BPSD-DS II, informant interviews were conducted to evaluate 524 individuals with DS grouped according to dementia status: no dementia (DS, N = 292), questionable dementia (DS + Q, N = 119), and clinically diagnosed dementia (DS + AD, N = 113). RESULTS: Comparing item change scores between groups revealed prominent changes in frequency and severity for anxious, sleep-related, irritable, restless/stereotypic, apathetic, depressive, and eating/drinking behavior. For most items, the proportion of individuals displaying an increased frequency was highest in DS + AD, intermediate in DS + Q, and lowest in DS. For various items within sections about anxious, sleep-related, irritable, apathetic, and depressive behaviors, the proportion of individuals showing an increased frequency was already substantial in DS + Q, suggesting that these changes may serve as early signals of AD in DS. Reliability data were promising. CONCLUSION: The optimized scale yields largely similar results as obtained with the initial version. Systematically evaluating BPSD in DS may increase understanding of changes among caregivers and (timely) adaptation of care/treatment.