A research study follows a group of individuals diagnosed with posttraumatic stress disorder (PTSD). At the start of the study, each participant undergoes a brain scan and completes a symptom severity questionnaire. The group then receives 12 weeks of cognitive-behavioral therapy. At the end of the 12 weeks, the brain scans and questionnaires are administered again. The results indicate that, on average, participants reported a significant decrease in symptom severity and the brain scans revealed a measurable increase in the volume of a specific brain structure critical for memory formation and stress regulation. Which of the following is the most accurate interpretation of these findings?