Recall and recognition as diagnostic indices of Malignant Memory Loss in Senile Dementia: a Bayesian analysis.

The Benign Senescent Forgetfulness of normal aging and the Malignant Memory Loss of Senile Dementia of the Alzheimer Type (SDAT) each have a distinct symptomatology, course, and prognosis. The purpose of this study was to evaluate the discriminative validity and relative predictive values of recall and recognition as diagnostic screening tests for the Malignant Memory Loss of SDAT. Thirty-six patients with mild to moderate SDAT and 40 normal aged controls were studied. Both recall and recognition showed good discriminative validity. However, analysis of recall and recognition by Bayes's Theorem revealed the relative predictive values as diagnostic screening instruments were 11% and 100% respectively. Thus, it was concluded that while both recall and recognition have discriminative validity under experimental conditions, a test of recognition is the preferred diagnostic instrument when screening for the Malignant Memory Loss of SDAT.