The aim of the present single case study was to demonstrate the effectiveness of a therapeutic evaluation model (CTA) used for 4 years with a teenage girl (13-17 years of age) with oppositional defiant disorder (ODD). Clinical evaluations using autobiography as well as the Millon Adolescent Clinic Inventory, House-Tree-Person Drawing, and Rorschach test (Comprehensive System) were conducted at each of four time points: 13, 14, 15, and 17 years of age. An average of four evaluation sessions were carried out at each time point following feedback of the results to the client, reflections about her experience with the evaluation process and with results obtained were requested in writing. Progressive findings reveal a gradual decrease in ODD markers and increasing sophistication, organization, and realism in the configuration of the drawings. The Rorschach test gradually indicated a decrease in aggression content and improvement in the quality of responses. In conclusion, the longitudinal design used in the case shows a strengthening of the self, a notable decrease in oppositional defiant behavior, and an adaptation and adjustment to reality as expected for a young woman of the client's age
