The Healthy Ageing Research Project, based at the School of Psychological Science is a longitudinal cohort study assessing some 120 community volunteers annually. The project has further links to other longitudinal cohort studies which evaluate how cognition changes at various points in the lifespan: the Raine study (which has followed 27 year-olds since before they were born!); the Busselton health study (a geographically based epidemiological study); and notably, the ParkC study (examining the factors that contribute to cognitive impairment and dementia in people with Parkinson's disease).
Critically, to employ neuroprotective treatment: early detection of cognitive impairment (MCI) and dementia- particularly in diseases like Alzheimer's and Parkinson`s disease is essential. Both MCI and dementia are defined by a strict set of diagnostic criteria. An individual's cognitive performance is assessed in a number of cognitive domains: memory, visuospatial, language, attention, processing speed and executive function. Test scores are then be compared to predicted scores for an individual of their age, gender and premorbid functioning (e.g. estimated IQ/ years education or that individual's previous scores, if available). For a diagnosis of dementia, functional difficulties (i.e. activities of daily living) must also be reported either by the patient, the caregiver, or a doctor. Similar criteria are specified by the Movement Disorders Society for the diagnoses of MCI and dementia in Parkinson's disease.
There is difficulty in manually processing both the HARP and ParkC data; a problem shared by many large cohort studies. It would be helpful for both research projects and clinical practice to have software in which relevant (often local) test norms could be programmed or uploaded; we could set an individual's premorbid function, and plug in test scores. The software could then flag patterns indicative of MCI or dementia for further investigation. While software won't remove the need for human oversight, with the increase in demand for neuropsychological screening for older adults, the application of a systematic data-driven approach is required.