Evaluation of Bizarre-Idiosyncratic Thinking Scale as a measure of thought disorder in children and adolescents with severe psychiatric disorders

To investigate the prevalence of thought disorder and the possible appropriateness of the Bizarre-Idiosyncratic Thinking Scale for children and adolescents with severe psychiatric disorders, 96 child and adolescent inpatients and day hospital patients, ages 6 to 18 years, at a state psychiatric hospital were rated by review of retrospective records using Marengo and Harrow's 1986 Evaluation of Bizarre-Idiosyncratic Thinking Scale for the presence of thought disorder in the Thematic Apperception Test and Rorschach Inkblot Test responses. Although the Evaluation of Bizarre-Idiosyncratic Thinking Scale had not been previously used with children and adolescents, the analysis suggested possible indications of thought disorder in several diagnostic groups. No significant differences were found on the Rorschach between patients with Schizophrenia and Psychosis, Not Otherwise Specified and those with Attention Deficit Hyperactivity Disorder, Major Depression, and Conduct Disorder. On the basis of the Thinking Scale ratings, the Thematic Apperception Test responses showed significantly higher ratings of thought disorder for patients with Schizophrenia and Psychosis, Not Otherwise Specified. There was no general relation between thought disorder and age or IQ, but schizophrenic patients, aged 13 and older, had more thought disorder than schizophrenic patients who were younger than 13.