Thought disorder in childhood schizophrenia: Replication and update of concept

Objectives: To examine whether measures of thought disorder differentiated schizophrenic from normal children and to examine the relationship of these measures with developmental and cognitive factors. Method: The speech samp les of 88 schizophrenic and 190 normal children, aged 9 to 13 years, were c oded with the Kiddie Formal Thought Disorder Rating Scale and Halliday and Hassan's analysis of cohesion. Results: Above and beyond differences in men tal age, gender, and neuroleptic status, the patients had significantly mor e formal thought disorder (FID) and cohesive deficits than the normal child ren matched by mental age. The younger schizophrenic and normal children ha d significantly more thought disorder than the older children with these di agnoses. Combined FTD and cohesion scores correctly identified 76% of schiz ophrenic and 88% of normal children with little variability across mental a ge. The thought disorder measures generated 2 independent components: FTD a nd cohesion. Conclusions: Thought disorder measures that include both FTD a nd cohesion provide a quantitative diagnostic tool of childhood-onset schiz ophrenia.