Background: Depression is the most common mental disorder in HIV infected patients. Despite the availability of efficacious treatments for depression, evidence suggests that it is under-diagnosed and under-treated in routine HIV care. To address this problem, the investigators will adapt and implement a collaborative stepped-care model for depression treatment in HIV clinics. This proposal builds on past success of the TIDES/WAVES programs used in VA primary care. The project (HI-TIDES or HIV Translating Initiatives for Depression into Effective Solutions) will implement the primary care collaborative care model for depression treatment in HIV clinics using evidence-based implementation strategies. Objectives: The objectives of this proposal are to: 1) Develop and evaluate the process of adapting, implementing, and sustaining collaborative care for depression in VA HIV clinics, 2) Compare the quality of depression care and the clinical effectiveness of HI-TIDES to usual care in the HIV clinics, and 3) Evaluate the cost-effectiveness of patients assigned to HI-TIDES relative to patients assigned to usual care in HIV clinics. Methods: The implementation framework for this proposal is primarily informed by the Rogers diffusion of innovation model, Simpson Transfer Model, and the PRECEDE model. The VA and American Psychiatric Association Practice Guidelines inform the stepped care collaborative model intervention as source documents for summarizing the evidence for depression treatment for the general population. An expert panel will be convened to rate the quality of available evidence for depression treatment in the context of HIV. Patients will be recruited from VA HIV clinics: Little Rock, Atlanta, and Houston. The intervention will be randomized at the level of the patient. The investigators expect to recruit a total of 140 intervention and 140 usual care patients. Patients in the intervention group will be supported by a depression collaborative care team that will include a depression nurse care manager, clinical pharmacist, and psychiatrist. The depression nurse care manager will evaluate depression symptom severity, antidepressant side effects, depression and HIV medication adherence every two weeks over the phone during the acute phase of treatment and will record these results in the VA electronic medical record. After a 50% improvement in depression severity, the intervention subject will move into the continuation phase of treatment and the patient will be contacted every four weeks by the depression nurse case manager. A formative evaluation will occur during start-up and throughout the implementation of the intervention. A summative evaluation will document the effectiveness and cost-effectiveness of the intervention using an intent to treat analysis plan. Findings: No results at this time. Status: Start-up activities. Impact: The proposed study is highly relevant to the VA and the Veterans it serves for many reasons. First, the majority of VA patients with HIV are not seen in the primary care clinics and therefore will not benefit from VA's efforts in primary care settings to improve depression identification and treatment. Second, in addition to the negative outcomes of depression generally, depression in HIV patients is associated with additional negative outcomes including accelerated HIV disease progression, decreased immune system functioning, and premature death. Third, directly moving collaborative depression care from primary care clinics to HIV clinics is likely to fail for several reasons including the comorbidities associated with depressed HIV patient and the potential for drug-drug interactions. The proposed project will address these gaps and provide effectiveness and cost-effectiveness analyses to inform decisions about larger scale implementation of the HI-TIDES intervention.