Evolution of Wechsler's Memory Scales: Content and structural analysis.

The Wechsler Memory Scale-1 was introduced to the professional community 70 years ago and has been the most widely used standardized memory battery for over 50 years. Since its introduction, the test has been revised three times, with the last revision occurring in 2009 . Few clinicians are aware that Wechsler developed a prior memory battery in 1917 , which was used to assess retention deficits in persons with Korsakoff psychosis. The purpose of the present article is to describe the development of Wechsler's memory scales from 1917 through 2009 . Suggestions for the next revision are offered.