Validation of a WAIS Algorithm for the Early Onset of Dementia

A WAIS algorithm was developed to distinguish between the onset of dementia and depression. Seven WAIS subtests were given to 148 patients whose diagnosis was doubtful. They were classified after a minimum of 1 yr. later as dementia ( n = 50) or as depression ( n = 98). The algorithm, developed from a discriminant function analysis, indicates dementia if the Vocabulary scaled score is greater than or equal to double the Block Design scaled score. The algorithm predicted 74% of the dementias and 74.5% of the depressions, for an over-all prediction rate of 74.3% (110 of 148 cases). These results indicate that the algorithm, if cross-validated, may be a useful adjunctive diagnostic tool in the differential diagnosis of early dementia from depression.