A review of four MMPI indices which differentiate between organicity and schizophrenia

Reviewed studies investigating the internal and external validity of four MMPI indices differentiating between schizophrenia and CNS disorders were contrasted and critiqued. Two types of test construction methods were identified as development procedures for the indices discussed, which were the item and profile analysis approaches. Although the indices developed by the profile analysis method proved more accurate in separating patients into the two diagnostic categories, hit rates were consistently affected by the degree of overlapping symptomatology between diagnostic sample groups. Variable hit rates reported for each of the indices ultimately lead one to question the MMPI's clinical utility for distinguishing patients presenting mixed organic and schizophrenic symptoms. Results from several studies converged on the conclusion that these MMPI indices measured a general degree of disturbance factor rather than schizophrenia or organicity.