This observational naturalistic study examined depression symptom change over the course of trauma-focused therapy. Understanding the impact of depression on trauma treatment and recovery as well as how to integrate therapeutic techniques for the treatment of concurrent depression and trauma, can assist with recovery from both conditions. Using naturalistic observations, depression symptom change was measured in 39 participants over the course of a triphasic trauma therapy called trauma practice (TP). Self-report measures were administered upon therapy initiation, following each therapy phase, and then at follow-up. Results demonstrated statistically and clinically significant improvements in depression symptoms following treatment. On average, clients shifted from clinically elevated depression symptoms at baseline to nonclinical symptoms at the conclusion of therapy. Notable effect sizes, clinically significant reliable change indices, and maintenance of treatment gains at follow-up were all present in this study, with the caveat that the sample size at follow-up was small. A strong, positive linear correlation was also found between depression symptom change and trauma symptom change over the course of treatment. TP appears to be a promising intervention for individuals with comorbid depression and trauma symptoms.