Discriminating psychotic and affective disorders using the WAIS-R

Although there are compelling theoretical explications linking performance on the Wechsler Adult Intelligence Scale (WAIS) with specific nosological groups, research findings have been inconsistent in demonstrating such relations. Three shortcomings can be identified within this literature: (a) it focuses mostly on the WAIS, (b) it relies on pre-Diagnostic and Statistical Manual of Mental Disorders (3rd ed. [DSM-III], American Psychiatric Association, 1980) criteria, and (c) it employs transformed scores or composite indices of WAIS performance. This article attempts to link performance variability on the WAIS-R (Revised) with diagnostic membership. The hypotheses of Rapaport, Gill, and Schafer (1968) are used to evaluate the clinical significance of the resulting discriminant equation.