A neuropsychological analysis of schizophrenic thought disorder

We examined the relationship of schizophrenic thought disorder, as measured by the Thought Disorder Index (TDI), with (1) neuropsychological measures of verbal memory, abstraction, executive function, visual memory, and working memory; and (2) quantitative MRI measures of prefrontal and basal ganglia structures. TDI scores correlated strongly with tests of verbal memory, abstraction and executive functions, modestly with tests of working memory, but did not correlate with scores on tests of visual memory. Neither TDI scores nor their neuropsychological correlates were associated with frontal or basal ganglia magnetic resonance imaging (MRI) measures, with the exception of the measures of working memory that demonstrated a modest relationship with frontal and basal ganglia structures. These findings suggest that schizophrenic thought disorder may be strongly related to neuropsychological impairments in verbal memory, abstraction and executive functions, and modestly related to problems with working memory in this sample of patients.