Effectiveness of Verbal Fluency Tests for Detecting Cognitive Decline in Adults with Alzheimer’s Dementia and Frontotemporal Dementia: A Three-Level Meta-Analysis

As our population ages, the prevalence of dementia, including Alzheimer’s dementia (AD) and frontotemporal dementia (FTD), is increasing. Early dementia diagnoses facilitate access to interventions when they are most effective for prolonging and improving life. Verbal fluency tests (e.g., FAS and Animal Fluency) can aid in the diagnosis of AD and FTD through detecting declines in executive functioning and language. These tests may be particularly useful for diagnosing the behavioural variant of FTD (bvFTD), which is associated with declines in executive functioning. A systematic search of Embase, PsycINFO, PubMed, MEDLINE, CINHAL, and AgeLine identified 127 peer-reviewed studies published from January 2010 to July 2024, which compared FAS and Animal Fluency Test performances of people with AD or FTD to cognitively-healthy controls. Hedges’ g effect sizes determined the effectiveness of three common score types (Total, Intrusion, Perseveration) for AD/FTD combined, AD and combined FTD subtypes, and AD and FTD subtypes (e.g., bvFTD). FAS and Animal Fluency Total Scores were the most reported and effective for detecting cognitive decline in these dementias combined ( g = -1.31 and g = -1.95, respectively), but similar effects were seen for AD and bvFTD. The pattern of effects was not influenced by patient characteristics and remained consistent when only low risk-of-bias studies were analysed. However, significant publication bias may have inflated the effects for AD. Overall, the FAS and Animal Fluency Total Scores can effectively detect cognitive decline in both AD and FTD, although they cannot be recommended for differentiating between AD and bvFTD.