Multiple choice vocabulary test MWT as a valid and short test to estimate premorbid intelligence

TLDR

The discrepancy between current and premorbid ability is a key indicator of acquired mental impairment, and verbal vocabulary tests—particularly the multiple‑choice MWT—have been shown to be valid and relatively insensitive to cerebral dysfunction, though only German versions exist. The study aims to present the MWT in detail, emphasizing its advantages as a short, sensitive tool for estimating premorbid intelligence. The MWT is constructed simply and can be administered in about five minutes, and the study discusses its limitations regarding diagnostic validity. The MWT correlates well with global IQ (median r = 0.72) and is more insensitive to current disturbances than the WAIS vocabulary test, leading the authors to conclude that studies failing to control premorbid intelligence constitute malpractice and should be rejected.

Abstract

The discrepancy between current and premorbid ability is a relevant indicator of acquired mental impairment, which itself is closely related to general cerebral dysfunction. The use of tests sensitive to cerebral dysfunction, raises relatively few problems compared with tests being resistent that are used to estimate premorbid mental ability. For premorbid ability, verbal tests assessing knowledge, especially vocabulary, have been shown to be valid. A test, possibly more insensitive to brain dysfunction than the ones usually administered, is the multiple choice vocabulary test (MWT = Mehrfachwahl-Wortschatz-Test). At present only German versions are available. They are presented in some detail because of their advantages. Construction of the MWT is simple, and it can be easily administered in about five minutes. The results correlate fairly well with global IQ in healthy adults (median of r = 0.72 in 22 samples) and are more insensitive to current disturbances than such tests as the WAIS vocabulary test. The limitations of premorbid tests with respect to diagnostic validity are discussed. It is concluded, that studies which do not control premorbid intelligence have to be considered as a "malpractice" and should not be accepted by scientists.