Predominant MMPI-168 profile clusters in a rehabilitation medicine sample.

Abstract

The MMPI-168 profiles of 120 rehabilitation medicine inpatients were clustered according to J. H. Ward's minimum-variance method, and four patient clusters were identified. The profile of mean MMPI-168 scores for the largest cluster, representing about onehalf of the total sample, showed no clinical elevations on any scale. The remaining three clusters were characterized primarily by depression, somatic focusing, and personality disorganization, respectively. Discriminant analysis supported the differentiation among clusters in terms of MMPI-168 scores and suggested that ruminative worry and openness to identifying problems accounted for the majority of the differentiation. With the exception of the cluster characterized primarily by depression, the three remaining clusters seemed quite similar to profile types consistently found in research on chronic pain samples.Research on the psychological aspects of physical disability is basic to the practice of psychology in rehabilitation medicine settings (Grzesiak, 1979). Efforts to describe the psychological characteristics associated with disabilities have often been based on "group averages." Common methodologies have included the description of samples with specified disability characteristics in terms of their mean scores on psychological measures, such as the Minnesota Multiphasic Personality Inventory (MMPI), or the comparison of their mean scores with those of other samples having different disability characteristics (Shontz, 1971). In reviewing research using the MMPI, McDaniel (1976) concluded that mean scores reported for samples with a variety of disabilities were consistently elevated one or more standard deviations above the mean on the first three clinical scales (Hs, D9 and Hy), the so-called "neurotic triad." Studies focusing on group averages ignore the preponderance of evidence suggesting that disability and behavior are linked in complex and indirect ways and that the psychological characteristics among individuals who are similarly disabled are typically diverse (