Some cognitive correlates of schizophrenic illnesses.

A battery of tests was developed to assess verbal, non-verbal and mixed cognitive functions. Interest was based on pattern of response rather than absolute scores. The subjects were 167 men held in prison on criminal charges or in a maximum security hospital after conviction. The present paper deals exclusively with two subgroups: the 61 schizophrenic men and the 41 men with no psychiatric disorder. The schizophrenic group as a whole presented a very different cognitive pattern from the 'normal' men. First, with the exception of the vocabulary subtest of the WAIS, the schizophrenics were inferior on all tests, whether verbal, non-verbal or mixed function. Secondly, they showed considerably more variation within subtests. The schizophrenic sample was therefore subdivided into four clinical groups. Each showed a distinctive cognitive profile. It is argued that these cognitive differences reflect real differences in the disorder and type of illness being experienced by members of these subgroups.