Digit symbol performance in mild dementia and depression.

Patients with mild dementia of the Alzheimer's type (DAT), patients with major depression, and normal control subjects completed the Wechsler Adult Intelligence Scale (WAIS) Digit Symbol test and a measure of incidental memory for the digit-symbol pairs. Mild DAT and depressed patients had equivalent deficits in psychomotor speed, but DAT patients recalled fewer digit-symbol items. Although the standard administration of the Digit Symbol test has limited utility in differential diagnosis, the addition of a brief measure of incidental memory may be clinically useful as part of the battery of neuropsychological tests used to distinguish early dementia from depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)