An MMPI scale to separate brain-damaged from functional psychiatric patients in neuropsychiatric settings.

Abstract

An empirical Minnesota Multiphasic Personality Inventory scale was developed to separate brain-damaged from functional psychiatric patients. It consisted of 56 items, which significantly differentiated organic and functional groups in a psychiatric hospital and was named the Psychiatric-Organic (P-O) scale. Upon cross-validation it was found capable of separating organics from process and reactive schizophrenics, alcoholics, and neurotics, as well as patients with character disorders and affective psychoses. Additionally it was found that by using the scale in combination with a traditional brain-damage test (the Benton Visual Retention Test), better discrimination could be achieved than was possible with either measure alone. The comparative probabilities of functional and organic diagnoses for various P-0 scale ranges are presented.The literature on the separation of braindamaged from nonorganic psychiatric patients via measures of ability is generally unencouraging. Attempts to differentiate organics from schizophrenics with such instruments as

MMPI-derived indicators of organic brain dysfunction

“…The MMPI forms for all Ss then were scored on eight experimental measures (Hovey, 1964;Russell, 1975;Shaw & Matthews, 1965;Watson, 1971;Watson & Plemel, 1978;Watson & Thomas, 1968) and the Sc scale of the MMPI.…”

“…Psychological and/or neurological testing results were screened to insure that a clear diagnosis of organicity or schizophrenia could be made. The MMPI forms for all Ss then were scored on eight experimental measures (Hovey, 1964;Russell, 1975;Shaw & Matthews, 1965;Watson, 1971; Watson & Plemel, 1978;Watson & Thomas, 1968) and the Sc scale of the MMPI.…”

“…These authors reported that no such patterns could be found. A second approach was taken by Hovey (1964), Shaw and Matthews (1965), Watson (1971), and Watson and Plemel (1978). They attempted to create "organicity scales" based on individual items taken from the MMPI.…”

Relative efficacy of the SC-O, P-O, P-N, and SC MMPI scales in differentiating brain-damaged, brain-damaged schizophrenic, schizophrenic, and somatoform disorders in an outpatient setting

“…Three of the MMPI special scales have demonstrated particular value in both of these instances. The special scales are the Schizophrenia-Organicity scale (Watson, 1971), the Psychiatric-Organic (P-0) scale (Watson & Plemel, 1978), the Pseudo-Neurological (P-N) scale (Shaw & Matthews, 1965). The Sc-0 scale was developed to differentiate organic from schizophrenic patients and has proved successful in 10 crossvalidation studies (Watson, 1984).…”

Differentiating brain damage from schizophrenia: A further test of Russell's MMPI key

“…As well, the Halperin, Neuringer, Davies, and Goldstein (1977) study failed to differentiate brain-damaged schizophrenics from non-brain-damaged schizophrenics with this measure. An additional scale was developed recently by Watson and Plemel (1978). The Golden et al (1979) crossvalidation found this scale able to discriminate between brain-damaged and normal medical patients who were suffering from backache and neck pain with a hit rate of 90% in the normal sample, but only 57% in the brain-damaged group, achieving an overall classification rate of 73%.…”