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© 2019 The Australian Psychological Society Objective: The prevalence of dementia and cognitive impairment is higher in Aboriginal Australians compared to the national population, increasing the need to understand cognitive impairment in this at-risk population. This article reports normative data for a range of commonly used cognitive tests, in a population-based small normative sample of older Aboriginal Australians living in urban/regional New South Wales. Method: Participants included a representative random sample of community-dwelling older adults (60 years and older) with no cognitive impairment (n = 31), mild cognitive impairment (MCI; n = 38), or dementia diagnosis (n = 35), all from the Koori Growing Old Well Study. Cognitive tests included the Addenbrooke's Cognitive Examination Revised (ACE-R), Digit Span (Forward and Backward), Logical Memory, and the Oral Trail Making Test (A and B). Results: Descriptive statistics and percentile scores for each test were reported for the normative sample. Comparison of performance between the diagnostic groups showed significant differences between the groups on most cognitive tests. The control group consistently performed better than the dementia group; and better than the MCI group on all tests, except for simple attention and sequencing tasks (Digit Span Forward and Oral Trail Making A). The MCI group also scored better than the dementia group on all tests, except for the Logical Memory Recognition task. Conclusion: Results support the utility of these cognitive tests that are commonly used in clinical and research settings, and demonstrate that these tests can discriminate between diagnostic groups in Aboriginal Australians. The normative data provided will enhance cognitive assessment of individuals within this population.

Dementia prevalence in Aboriginal and Torres Strait Islander Australians is three to five times higher than the general Australian population. A better understanding of the underlying biomedical and social risk factors is needed to guide dementia prevention in Aboriginal Australians. The current study is the first to examine potential risk factors for dementia in the majority urban and regional population, with a representative sample of 336 Aboriginal Australians aged 60 years and older. Participants included 45 people with a dementia diagnosis (n = 27 probable/possible Alzheimer’s disease); and 286 people without dementia. Univariate logistic regression analyses (controlling for age) identified childhood trauma, mid-life factors (history of unskilled work, past high-risk alcohol use), and medical factors (history of stroke, head injury with loss of consciousness, epilepsy) as risk factors for dementia. Multivariable analysis revealed age, childhood trauma, unskilled work, stroke, and head injury as independent predictors of all-cause dementia. A range of comorbid factors related to dementia was also identified (i.e., functional impairment, incontinence, recent hospital admission, low body mass index, living in residential care, depression, current high-risk alcohol use, social isolation, low physical activity levels). These findings extend previous outcomes in a remote Aboriginal population by highlighting that life-course social determinants of health, in addition to neurological disorders, likely play an important role in elevating dementia risk. Certain psychosocial and medical exposures are highly prevalent in Aboriginal Australians, similar to other indigenous populations, and should be considered when designing targeted and culturally appropriate prevention initiatives to reduce the burden of dementia. NHMRC, NHMRC-ARC Dementia Research Development Fellowship, Serpentine Foundation Fellowship

This study aimed to document change in neuropsychological, physical and functional performance over one year and to investigate the relationship between baseline gait speed and cognitive decline in this period in older people with dementia.One hundred and seventy-seven older people with dementia (Mini-Mental State Examination 11-23; Addenbrooke's Cognitive Examination-Revised83) residing in the community or low level care facility completed baseline neuropsychological, physical and functional assessments. Of these, 134 participants agreed to reassessment of the above measures one year later.Overall, many neuropsychological, physical and functional performance measures declined significantly over the one year study period. Baseline gait speed was significantly associated with decline in verbal fluency (B(109)=2.893, p=0.046), specifically phonemic/letter fluency (B(109)=2.812, p=0.004) while controlling for age, education, dementia drug use and baseline cognitive performance. There was also a trend for an association between baseline gait speed and decline in clock drawing performance (B(107)=0.601, p=0.071).Older people with mild to moderate dementia demonstrate significant decline in neuropsychological, physical and functional performance over one year. Baseline gait speed is associated with decline in executive function over one year, suggesting shared pathways/pathology between gait and cognition.