The Diagnostic Significance of Overinclusive Thinking in an Unselected Psychiatric Population

Abstract

Cameron (1938, 1939) suggested that schizophrenic thought disorder is largely the result of overinclusive thinking, which he defined as the inability to preserve conceptual boundaries. Payne, Matussek and George (1959) developed a battery of objective measures of overinclusive thinking, which they found differentiated between an acute schizophrenic and a neurotic control group. Payne and Hewlett (1960) found that a battery of tests of overinclusive thinking intercorrelated as expected. They were able to obtain a factor score from their overinclusion test battery which differentiated a group of acute schizophrenic patients from control groups of depressives, neurotics and normal subjects. Payne and Friedlander (1962), on the basis of this factorial study, suggested a short battery of three measures of overinclusive thinking consisting of the number of ‘Non-A’ or unusual responses to the Object Classification Test (Payne, 1962), the average number of words used in explaining the Benjamin Proverbs given under special 'stress free’ instructions, and the average number of objects classified together in the ‘handing over’ section of the Goldstein-Scheerer Object Sorting Test. This standard test battery has been the operational definition of overinclusive thinking in a number of studies. Only one study of the reliability of this test battery appears to have been carried out. Hawks and Payne (1971) report the correlations obtained from a group of 54 psychiatric inpatients who were retested after a 4-day interval. The test-retest correlation coefficient (uncorrected) obtained from the Combined Transformed score (Payne and Friedlander, 1962) was 0 · 87. The reliabilities of the individual tests ranged from 0·77 to 0·86.

Behavioral overinclusion as a prognostic index in schizophrenic disorders.

“…During their research with various indexes of overinclusion in schizophrenic disorders, the current investigators found that the index of conceptual overinclusion differentiated schizophrenic from nonschizophrenic patients at the acute stage but found more mixed results with the index of behavioral overinclusion derived from the Object Sorting Test (Harrow, Himmelhoch, Tucker, Hcrsh, & Quinlan, 1972). More recently, Payne and colleagues also failed to find positive results on schizophrenic, patients using indexes of behavioral overinclusion on an unselectedpsychiatricpopulation, although they noted that these indexes may still have prognostic utility (Payne, Hawks, Friedlander, & Hart, 1972). The present research was designed to confirm the finding of Payne that measures of behavioral overinclusion during the acute state are of prognostic utility in schizophrenic disorders.…”

“…3 Other results supporting this position have been reported recently by Payne using an unselected sample of patients (Payne,3 Thirty-eight patients from the present sample overlap with a sample of patients studied previously at the acute stage (Harrow, Himmelhoch, Tucker, Hersh, & Quinlan, 1972), and 47 patients overlap with a sample studied during partial recovery (Harrow, Tucker, Himmelhoch, & Putnam, 1972). Hawks, Friedlander, & Hart, 1972). '' Since the total number of objects sorted is not a direct measure of disordered thinking, other indexes would seem to be more appropriate for assessing overinclusivc thinking (Harrow, Himmelhoch, Tucker, Hersh, & Quinlan, 1972) and for assessing other aspects of disturbed schizophrenic thinking (Harrow, Tucker, & Adler, 1972;Quinlan, Harrow, Tucker, & Carlson, 1.972).…”

Object-name selection in psychiatric patients before and after neuroleptic therapy

“…The question of medication has been inconsistently tackled in previous studies of overinclusion. Some failed to take it into account (Foulds et al, 1967;Andreasen and Powers, 1974) while others, who did recognize the importance of a drug-free interval, either failed to specify it (Payne et al, 1972) or used an inadequate interval (Payne et al, 1963). A previous study of the effects of phenothiazines on overinclusive thinking, measured by performance on a proverbs test (Chapman et al, 1975) found that overinclusiveness was reduced in some patients (though increased in others) by drug withdrawal.…”

A test of Chapman's theory of schizophrenic thought disorder.

“…This conclusion is in agreement with the results of other investigators of psychological deficit in schizophrenia. In those studies, measures that previously had been shown to differentiate hospitalized schizophrenics from normal controls failed to distinguish schizophrenics from a general sample of hospitalized psychiatric patients (Bromet & Harrow, 1973;Kopfstein & Neale, 1972;Payne, Hawks, Friedlander, & Hart, 1972;Sturm, 1965). Considering that the performances of the less severely disturbed patients in this study were nearly equivalent and that their mean scores on the experimental task fell between those obtained by the nonhospitalized normals and severely disturbed patients in Boland and Chapman's (1971) study, certain unidentified and diagnostically nonspecific traits such as chronicity and/or severity of the psychopathology might better account for the obtained results.…”