An examination of the California Verbal Learning Test II to detect incomplete effort in a traumatic brain-injury sample.

Clinical neuropsychologists are frequently called on to distinguish people who appear impaired on neuropsychological testing due to putting forth incomplete effort from those who have genuine cognitive deficits. Because traditional measures of effort are becoming accessible over the Internet and within the legal community and their purpose may be obvious to potential malingerers, nontraditional effort measures have been newly investigated. Using discriminant function analysis, this study explores whether five California Verbal Learning Test-Second Edition (CVLT-II) variables could differentiate between head-injured patients who were putting forth full effort and those who were putting forth incomplete effort. The discriminant function seemed to best predict those who put forth adequate effort while testing (95.6% correct) but not those who failed to put forth adequate effort during testing (only 13.8% correct). Hence, although the overall classification rate was moderately impressive (75.8%), the model's sensitivity in classification of the incomplete effort group was low. Cautious applications for these findings are discussed.