Testing the limits: cautions and concerns regarding the new Wechsler IQ and Memory scales.

The Wechsler Adult Intelligence Scale (WAIS) and the Wechsler Memory Scale (WMS) are 2 of the most common psychological tests used in clinical care and research in neurology. Newly revised versions of both instruments (WAIS-IV and WMS-IV) have recently been published and are increasingly being adopted by the neuropsychology community. There have been significant changes in the structure and content of both scales, leading to the potential for inaccurate patient classification if algorithms developed using their predecessors are employed. There are presently insufficient clinical data in neurologic populations to insure their appropriate application to neuropsychological evaluations. We provide a perspective on these important new neuropsychological instruments, comment on the pressures to adopt these tests in the absence of an appropriate evidence base supporting their incremental validity, and describe the potential negative impact on both patient care and continuing research applications.