Since many schizophrenics regress cognitively to the point of mental deficiency, the distinction between true (developmental) and functional retardation in the adult poses a recurrent diagnostic problem. Intelligence tests do not resolve the issue, which pivots on the question of whether cognitive processes, though deviant, have fully matured. The present study examined the ability of a series of developmentally rooted cognitive tests and other measures to differentiate between mentally and functionally retarded schizophrenics matched for IQ, sex, and race. Those with true retardation were found to be more primitive in their conceptual strategies, shorter in attention span, and slower in psychomotor pace. As a group, they tended to be younger, hospitalized earlier in life, and less variable on most tests. Optimal performance on each of six measures from the Cognitive Diagnostic Battery provided a statistical basis for ruling out mental retardation in the schizophrenic.
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References
1.
American Psychiatric Association. (1980). Diagnostic and statistical manual of mental disorders. (3rd ed.) Washington, DC: Author.
2.
Ammons, R.B., & Ammons C.H. (1962). The Quick Test (QT): Provisional manual. Psychological Reports, 11, 111-161. (Monograph Supplement 1-VII)
3.
Batman, R.H., Albee, G.W., & Lane, E.A. (1966). Intelligence test performance of chronic and recovered schizophrenics. Proceedings of the 74th annual meeting of the American Psychological Association. Washington, DC: American Psychological Association.
4.
Bearison, D.J., & Sigel, I.E. (1968). Hierarchical attributes for categorization. Perceptual and Motor Skills, 27, 147-153.
5.
Birch, H.G., Richardson, S.A., Baird, D., Horobin, G., & Illsley, R. (1970). Mental subnormality in the community: A clinical and epidemiological study. Baltimore: Williams & Wilkins.
6.
Blatt, S.J. (1959). Recall and recognition vocabulary: Implications for intellectual deterioration. Archives of General Psychiatry,1, 473-476.
7.
Blatt, S.J., & Wild, C.M. (1976). Schizophrenia: A developmental analysis. New York: Academic Press.
8.
Chapman, L.J., & Chapman, J.P. (1978). The measurement of differential deficit. Journal ofPsychiatric Research, 14, 303-311.
9.
Dizzonne, M.F., & Davis, W.E. (1973). Relationship between Quick Test and WAIS IQs for brain-injured and schizophrenic subjects. Psychological Reports , 32, 337-338.
10.
Doll, E.A. (1965). Vineland Social Maturity Scale: Condensed manual of directions. Circle Pines, MN: American Guidance Service.
11.
Graham, F.K., & Kendall, B.S. (1960). Memory-For-Designs Test: Revised general manual . Perceptual and Motor Skills, 11, 147-188. (Monograph Supplement 2-VII)
12.
Grossman, H. (1977). Manual on terminology and classification in mental retardation. Washington, DC: American Association on Mental Deficiency.
13.
Harrow, M., Tucker, G.J., & Adler, D. (1972). Concrete and idiosyncratic thinking in acute schizophrenic patients. Archives of General Psychiatry, 26, 433--439.
14.
Harrow, M., Tucker, G.J., Himmelhoch, J., & Putnam, N. (1972). Schizophrenic "thought disorder" after the acute phase. American Journal of Psychiatry,128, 824-829.
15.
Kay, S.R. (1977). Developmental assessment of cognitive style in mentally retarded psychotics. Journal of Clinical Psychology , 33, 953-958.
16.
Kay, S.R. (1978). Qualitative differences in human figure drawings according to schizophrenic subtype. Perceptual and Motor Skills47, 923-932.
17.
Kay, S.R. (1979a). Maturity of schizophrenic conceptual style in relation to intelligence. Perceptual and Motor Skills, 48, 1286.
18.
Kay, S.R. (1979b). Significance of torque in retarded mental development and psychosis: Relationship to antecedent and current pathology. American Psychologist, 34, 357-362.
19.
Kay, S.R. (1980). Progressive figure drawings in the developmental assessment of mentally retarded psychotics. Perceptual and Motor Skills, 50, 583-590.
20.
Kay, S.R. (1982). The Cognitive Diagnostic Battery: Evaluation of intellectual disorders. Odessa, FL: Psychological Assessment Resources.
21.
Kay, S.R., & Singh, M.M. (1974). A temporal measure of attention in schizophrenia and its clinical significance. British Journal of Psychiatry , 125, 146-151.
22.
Kay, S.R., & Singh, M.M. (1975). A developmental approach to delineate components of cognitive dysfunction in schizophrenia. British Journal of Social and Clinical Psychology, 14, 387-399.
23.
Kay, S.R., & Singh, M.M. (1979). Cognitive abnormality in schizophrenia: A dual-process model. BiologicalPsychiatry, 14, 155-176.
24.
Kay, S.R., Singh, M.M., & Smith, J.M. (1975). Color Form Representation Test: A developmental method for the study of cognition in schizophrenia. British Journal of Social and Clinical Psychology, 14, 401-411.
25.
Opler, L.A., Kay, S.R., Rosado, V., & Lindenmayer, J.P. (1984). Positive and negative syndromes in chronic schizophrenic inpatients. Journal of Nervous and Mental Disease, 172, 317-325.
26.
Payne, R.W. (1973). Cognitive abnormalities. In H. J. Eysenck (Ed.), Handbook of abnorrnal psychology. London: Pitman Medical .
27.
Phillips, I., & Williams, N. (1975). Psychopathology and mental retardation: I. Psychopathology . American Journal of Psychiatry,132, 1265-1271.
28.
Reiss, S., Levitan, G.W., & McNally, R.J. (1982). Emotionally disturbed mentally retarded people: An underserved population. American Psychologist, 37, 361-367.
29.
Singh, M.M., & Kay, S.R. (1976). Wheat gluten as a pathogenic factor in schizophrenia . Science, 191, 401-402.
30.
Singh, M.M., & Kay, S.R. (1982). Towards a psychobiological model of schizophrenia: A clinical neuroscientist's view. In M. Namba & H. Kaiya (Eds.), Psycho-biology of schizophrenia. Oxford: Pergamon.
31.
Sternberg, R.J. (1981). Testing and cognitive psychology. American Psychalogist, 36, 1181-1189.
