This article presents a study protocol for evaluating a psychometric scale designed to identify distinctive elements in the drawings of individuals with psychotic symptoms. The study aims to validate the “Scale of Distinctive Elements in the Drawings of Subjects with Psychotic Symptoms,” a tool that evaluates 25 specific features in drawings, including ambiguity, disorganization, stereotypy, and oddity. The research involved two groups: 40 participants with psychotic symptoms and 100 healthy controls. These participants created drawings that were subsequently evaluated by trained raters. The study employed both exploratory and confirmatory factor analyses to evaluate the scale’s structure and validity. The research highlights the potential of art therapy as an adjunctive treatment for schizophrenia, providing insights into the mental state of patients that are challenging to capture through verbal methods alone. The development of this scale addresses the need for standardized tools to assess the effectiveness of art therapy, particularly in individuals with severe psychiatric disorders. However, the study also acknowledges the limitations of existing literature and emphasizes the importance of considering cultural and individual differences in art creation and interpretation. Overall, this study protocol outlines a comprehensive approach to assessing distinctive features in the art of individuals with psychotic symptoms, aiming to enhance the diagnostic and therapeutic utility of art therapy in clinical settings.