Objective: The objective of the study was to evaluate from the perspective of the Piaget developmental model the cognitive functioning of a sample of patients diagnosed with schizophrenia.
Method: Fifty patients with schizophrenia (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) and 40 healthy matched controls were evaluated by means of the Longeot Logical Thought Evaluation Scale.
Results: Only 6% of the subjects with schizophrenia reached the "formal period," and 70% remained at the "concrete operations" stage. The corresponding figures for the control sample were 25% and 15%, respectively. These differences were statistically significant. The samples were specifically differentiable on the permutation, probabilities, and pendulum tests of the scale.
Conclusions: The Longeot Logical Thought Evaluation Scale can discriminate between subjects with schizophrenia and healthy controls.