Assessment of disordered thinking in children and adolescents: the rorschach perceptual-thinking index.

The new Rorschach Perceptual-Thinking Index (PTI; Exner, 2000a, 2000b) was designed to assess thought disorders more accurately than the Schizophrenia Index (SCZI; Exner, 1993). Using a sample of child and adolescent inpatients, we examined the relation of Rorschach variables (PTI, SCZI, M-, and X- %) to thought disorder indexes on a behavior rating scale (Behavior Assessment System for Children; Reynolds & Kamphaus, 1992) and a self-report measure (Personality Inventory for Youth; Lachar & Gruber, 1995). Results indicate that, when used in a categorical manner, the PTI differentiated between those patients with and without elevated thought disorder scores on the other measures. Of all Rorschach variables, M- was most related to the other measures, indicating that this variable may be a particularly robust indicator of thought disorder among children and adolescents.