The Verbal Fluency Test for Dementia Screening

The verbal fluency test (VFT) is a short screening test that evaluates cognitive function. It’s often used by physicians and other practitioners if there is some concern that the person may have Alzheimer’s or another type of dementia.

Test Methods

By its name, you might guess that the test has something to do with speaking and speed, and you would be correct. The test consists of giving the person 60 seconds to verbally list as many things as possible in a category. Practitioners often use the verbal fluency test in two different ways:

Semantic/Category Subtest

The person is asked to list all of the animals he can think of in the next 60 seconds. Some variations include asking the test-taker to list all of the fruits, vegetables or the professions he can think of in 60 seconds.

Phonetic/Letter Subtest

In the phonetic subtest, a letter is chosen by the test administrator and the person is asked to name all of the words that begin with that particular letter. The most common letters chosen are F, A, and S. Some clinicians will have the individual do a 60-second test on each letter, and others will just choose one letter. 

Scoring 

To score the VFT, count up the total number of animals or words that the individual is able to produce. Norms for the scoring are based on age and education for each test.

Accuracy 

Research has shown that the semantic VFT, in particular, is comparable to both the MMSE and the Clinical Dementia Rating scores, two other tests frequently used in cognitive testing. The semantic subtest has also been shown to be quite effective in measuring executive functioning and language ability. This may be because the semantic/category subtest seems to require a higher level of thought processes since people have to think of meaning rather than just beginning sounds of words.

The phonetic subtest does not appear as sensitive to the early stages of dementia; however, the test results as people age are quite stable, making it a valuable tool. If someone scores poorly on the phonetic subtest, it is quite likely an indicator of cognitive decline rather than older age.

Pros 

• Very brief. The VFT, including both subtests, generally takes anywhere from three to ten minutes to complete from start to end. One section of this test can be completed by the individual in 60 seconds.
• Quite accurate in screening for dementia. As noted above, the VFT is a quick and relatively accurate way to assess someone's cognitive functioning.
• Little resistance or refusal to participate. Most people agree to take this test and complete it. This may be because listing off words doesn't sound too intimidating to people, and a 60 seconds time limit might also encourage test completion.
• No cost. Unlike some other cognitive tests where you must purchase test copies and instructions booklets, the VFT has no cost.
• Easy to administer. The VFT does not require extensive training before administration of the test.
• Does not require other materials. No materials are needed to conduct this test other than a timing device and a way to track the number of words the person produces.

Cons

• Performance can be influenced by the level of education and age. Several research studies have documented that the amount of education as well as the person's age (specifically in the semantic subtest) affect performance and should be factored in when using the VFT.
• The VFT should be used in combination with other screenings for dementia. A diagnosis of dementia should not be solely based on the VFT. Other, more thorough screenings, as well as medical testing and blood work, should be utilized if a person demonstrates difficulty with this test.