The long-term protective effect of self-awareness in substance use disorders, described as a type of brain disease, is currently being discussed and is called tertiary prevention. The aim of this study was to demonstrate the contribution of a positive psychotherapy program implemented in tertiary prevention by repeatedly measuring patients’ levels of harm perception and result awareness. One-group pre-test post-test experimental model was used according to the quantitative method. The sample of the study consisted of 44 patients who applied to AMATEM and were diagnosed with substance use disorder and/or alcohol use disorder and comorbid bipolar disorder. Two groups were formed by taking into account comorbidities: The first group consisted of 30 individuals with substance use disorder and/or alcohol use disorder. The second group consisted of 14 patients diagnosed with bipolar disorder together with substance use disorder. The data were collected with the Uskudar Harm Perception Scale (USHPS) and the Uskudar Result Awareness Scale (USRAS), developed by Tarhan, Demirsoy and Tutgun-Ünal. As a result of the study, the pre-test and post-test scores of the patients differed, and their awareness levels increased after the psychotherapy program. It was understood that the program and measurement tools contributed to the tertiary prevention studies.