Project Summary/Abstract The objective of this project is to improve the treatment of depression in cancer patients. Up to 25% of people with cancer will become clinically depressed, significantly affecting their quality of life and functioning. Depression has been associated with a decreased ability to tolerate and complete cancer treatment, as well as significantly increased healthcare costs. Unfortunately, about 75% of cancer patients with depression do not receive adequate treatment, and patients in rural settings are even less likely to receive adequate treatment. Reasons for this large treatment gap include: (1) lack of standard processes for psychosocial follow-up and treatment adjustments; (2) inadequate availability of mental health clinicians with experience in behavioral and psychopharmacologic treatment of cancer patients; (3) patient inability to follow up with psychosocial treatment due to medical illness, financial barriers, and transportation and other logistical barriers; and (4) ongoing stigma and lack of engagement related to mental health care. Collaborative Care Management (CoCM) is an evidence-based system of care that has been shown to lead to sustained improvement in depression symptoms and quality of life in patients with cancer and other medical conditions. CoCM is a population-based, integrated care approach, where care managers, who are clinicians such as social workers, nurses or psychologists, deliver behavioral treatments, coordinate psychosocial care, monitor outcomes, and adjust treatment with the input of a psychiatric consultant. Although the CoCM model has been shown in a recent meta-analysis to be highly effective in the cancer setting, high-fidelity implementation has been slow, particularly in low-resourced and rural areas. The use of technology has the potential to enhance implementation and fidelity of CoCM in diverse cancer settings. This proposed study will use a human-centered design approach to develop, build, and test a web and mobile platform to enhance the implementation and fidelity of CoCM of depression for patients being treated at urban and rural cancer centers. In Phase I of the study, patient-facing web and mobile applications and a clinician-facing website will aim to: (1) enhance treatment engagement among patients and clinicians; (2) collect timely patient-reported outcomes for measurement-based care; (3) promote patient-centered shared decision-making for better treatment adjustments; and (4) maximize adherence to evidence-based guideline-level behavioral and pharmacologic treatments. In Phase II of the study, the technology-enhanced CoCM system (t-CoCM) will be compared to usual CoCM (u-CoCM) in a pragmatic Hybrid Type 1 effectiveness-implementation randomized controlled trial to evaluate their ability to achieve optimal fidelity of CoCM and clinical outcomes.