Word sequence production in cognitive decline: forward ever, backward never

Backward recall of automatic word sequences involves declarative and working memory abilities known to be impaired in the early stages of cognitive decline. Yet its utility in the diagnosis of mild cognitive impairment and mild dementia has not been studied in detail. We analysed word sequence production in 234 participants drawn from three categories: subjective cognitive impairment, mild cognitive impairment, and mild dementia in Alzheimer's disease. The names of the months were used as a diagnostic target for investigating forward versus backward sequence production. Forward production remained normal across categories. In contrast, backward speed was significantly decreased in mild cognitive impairment. In dementia both speed and accuracy were impaired. Backward production had significant diagnostic classificatory power. We conclude that word sequence production yields data relevant to the diagnosis of dementia with a minimum of time and expense.