Assessing risk taking and decision making associated with late‐life onset mild psychotics symptoms in cognitively normal older adults
Zahinoor Ismail, Dag Aarsland, Clive G Ballard, Anne Corbett, Byron Creese- Psychiatry and Mental health
- Cellular and Molecular Neuroscience
- Geriatrics and Gerontology
- Neurology (clinical)
- Developmental Neuroscience
- Health Policy
- Epidemiology
Abstract
Background
Late‐life onset psychosis assessed in the Mild Behavioral Impairment framework (MBI‐psychosis) is a risk factor for dementia and known to be associated with impaired reasoning and memory in people without dementia. There is evidence that psychotic symptoms across diagnostic boundaries share some common genetic and neuropsychological correlates. In this study we aimed to determine whether MBI‐psychosis is associated cognitive deficits typically associated with other psychoses. To do this, we examined the relationship between MBI‐psychosis and scores on a specialised decision making and risk‐taking test, the Cambridge Gambling Task (CGT), performance on which is impaired in people with earlier life psychotic syndromes.
Method
476 participants were drawn from the online PROTECT registry on the basis of the Mild Behavioural Impairment Checklist (MBI‐C) ratings indicating psychosis and invited to complete the Cambridge Gambling Task. The association between performance on six CGT outcome measures, assessing elements of risk taking and decision making, and MBI‐psychosis was tested using linear regression (controlling for age, sex and education level).
Result
Overall, there was little evidence of a substantial impact of MBI‐psychosis on CGT scores. Our study was powered to detect medium effect sizes. We found modest evidence of higher risk taking associated with more severe MBI‐psychosis scores (β = ‐0.1, SE = 0.05, p = 0.04) but this did not survive multiple testing correction.
Conclusion
This is the first time a specialist decision making and risk‐taking test has been conducted in MBI‐psychosis. Although MBI‐psychosis is associated with a range of cognitive impairments in later‐life and dementia risk it appears that any shared neuropsychological basis with other psychoses is limited (though we cannot rule out a small non‐clinically significant effect size). This has possible implications for the diagnostic classification of later‐life onset mild psychotic symptoms.