The Early Presentation of Dementia in People with Down Syndrome: a Systematic Review of Longitudinal Studies.

Adults with Down syndrome (DS) are at a very high risk of developing early onset Alzheimer's disease (AD) due to trisomy of chromosome 21. AD is preceded by a prolonged prodromal "pre-clinical" phase presenting with clinical features that do not fulfil the diagnostic criteria for AD. It is important to clinically characterise this prodromal stage to help early detection of the disease as neuropathology of AD is almost universal by the fifth decade in DS. There is a lack of knowledge of the trajectory of decline associated with the onset of dementia in this population and early signs may be overlooked or misdiagnosed, negatively affecting the quality of life of those affected and the use of early pharmacological or psychosocial interventions. The objective of this systematic review is to evaluate the published literature on longitudinal data in order to identify the cognitive and behavioural changes occurring during the prodromal and early stages of AD in this population. Fifteen peer-reviewed articles met the inclusion criteria, including a total number of 831 participants, with the duration between baseline and follow up varying from 1 year to 47 years. Results suggest that, compared to the general population for which short-term (episodic) memory loss is the most common indicator associated with the onset of AD, in people with DS, executive dysfunction and Behavioural and Psychological Symptoms of Dementia (BPSD) are commonly observed during pre-clinical and early stages and may precede memory loss. The review highlights the importance of using a broad spectrum of assessments in the context of heterogeneity of symptoms. Theoretical and practical implications are discussed, as well as the need for further research.

Participant experience of invasive research in adults with intellectual disability.

Clinical research is a necessity if effective and safe treatments are to be developed. However, this may well include the need for research that is best described as 'invasive' in that it may be associated with some discomfort or inconvenience. Limitations in the undertaking of invasive research involving people with intellectual disabilities (ID) are perhaps related to anxieties within the academic community and among ethics committees; however, the consequence of this neglect is that innovative treatments specific to people with ID may not be developed. Such concerns are likely to continue while there is limited published knowledge regarding the actual experiences of people with ID who have participated in invasive clinical research. As part of a pilot study trialling the novel use of a surgically inserted device to curb overeating in people with Prader-Willi syndrome (PWS) we have investigated the experience of research through semistructured qualitative interviews involving three participants and their carers. Thematic analysis revealed that the adults with PWS and their family carers rated their participation positively, seeing it as a rewarding and enriching experience. This brief report discusses findings from our interview data in order to highlight strategies which may ensure that research is acceptable to participants, meets the necessary ethical standards and is able to achieve the aims set out by the researchers. To our knowledge, this is the first study to record experiences directly from people with PWS and their carers regarding their involvement in invasive clinical research.