Normal aging and pseudo-dementia
Normal Aging: as we get older, cognitive abilities change slightly.
Beginning about age 25, numerical ability/arithmetic and processing speed starts to slowly declines. In the 40’s, 50’s to 60’s, some aspects of memory declines slightly (episodic memory). However, word knowledge, vocabulary, word reading generally remains stable into late adulthood (70’s+). These changes are usually minor and naturally compensated for by the aging individual.
When changes in cognition are greater than what can be expected for age, we may wonder about :
- Mild Cognitive Impairment (or Minor Neurocognitive disorder, as per DSM-5) can be defined as an ‘abnormal’ decline in cognitive function greater than expected for age.
- Dementia (or Major Neurocognitive disorder, as per DSM-5) can be defined as a decline in previously acquired cognitive and behavioral abilities which leads to deficits in ability to function
Most importantly, with aging, individuals become more sensitive to the effect of stress, which can limit our ability to fully use our cognitive resources.
For example, clinicians historically designed this as “Depressive Pseudodementia”: when older people exhibited symptoms consistent with dementia but the cause was actually Depression (mood). Even if the term Pseudodementia is not used as often nowadays, the idea remains. The differential diagnosis between these 2 conditions can be quite complex and the two often overlap. Diagnosis by a skilled neuropsychologist is often required.
For more info about this topic, read publications by Sonia Lupien, Ph. D., researcher based in Montreal and Scientific Director at the Fernand-Seguin Research Center for more research on the effect of stress on cognition in aging individuals. http://www.iusmm.ca/research/researchers/researchers/sonia-lupien.html
Detailed neuropsychological evaluation assists differential diagnosis. It might help tease apart the effect of stress VS aging. If there are cognitive deficits, neuropsychological evaluation should help Identify subtypes of MCI, Differential diagnosis of dementias, Allow early detection, Start treatment planning with a physician, Determining care needs (placement), Determining competency/functional capacity.