The Schizophrenia State Inventory (SSI), developed to assess major dimensions of schizophrenia, has in the past revealed significantly greater dysfunctioning for schizophrenics as a group vs. nonschizophrenics along six of seven areas of clinical pathology: a) language; b) dysphoria; c) integration of self; d) thinking; e) general affect; and f) perception. The present investigation replicates and extends the original findings on a new sample of 119 patients, and combines both samples for a factor analysis, further elaborating the meaningfulness of the SSI.
The original findings were replicated on the new, independent sample of 119 patients. On the scales of Language, Self-Integration, Thinking and Perception, means for the schizophrenic group were at least one full scale point greater than for the nonschizophrenic group. Mean differences for the scales of Dysphoria and Affect were also statistically significant.
A factor analysis on a combined sample of 224 patients was conducted on 37 major variables derived from the research interview. This analysis revealed a first major factor, labeled clinical psychosis, comprised of variables suggesting that it indexed important clinical features of both psychosis and severe acute psychopathology. Additional support for the interpretation of the factor as one of clinical psychosis was found when further analysis was conducted in which each individual subject's factor scores were computed and a t-test contrasted the schizophrenic and nonschizophrenic groups. The difference between the two groups was significant (p < .001). Scores from the three other major factors related to aspects of premorbid functioning and other clinical features did not discriminate between these two groups.
The clinical relevance of these results is explored with special emphasis given to the SSI as a particularly meaningful way of understanding the clinical experiences of young schizophrenic patients during phases of acute psychopathology.