Key Points• Depression was found in 35.2% of adult SCD patients and was strongly associated with worse physical and mental quality-of-life outcomes.• Total health care costs for adult SCD patients with depression were more than double those of SCD patients without depression.Sickle cell disease (SCD) is a chronic, debilitating disorder. Chronically ill patients are at risk for depression, which can affect health-related quality of life (HRQoL), health care utilization, and cost. We performed an analytic epidemiologic prospective study to determine the prevalence of depression in adult patients with SCD and its association with HRQoL and medical resource utilization. Depression was measured by the Beck Depression Inventory and clinical history in adult SCD outpatients at a comprehensive SCD center. HRQoL was assessed using the SF36 form, and data were collected on medical resource utilization and corresponding cost. Neurocognitive functions were assessed using the CNS Vital Signs tool.Pain diaries were used to record daily pain. Out of 142 enrolled patients, 42 (35.2%) had depression. Depression was associated with worse physical and mental HRQoL scores (P , .0001 and P , .0001, respectively). Mean total inpatient costs ($25 000 vs $7487, P 5 .02) and total health care costs ($30 665 vs $13 016, P 5 .01) were significantly higher in patients with depression during the 12 months preceding diagnosis. Similarly, during the 6 months following diagnosis, mean total health care costs were significantly higher in depressed patients than in nondepressed patients ($13 766 vs $8670, P 5 .04). Depression is prevalent in adult patients with SCD and is associated with worse HRQoL and higher total health care costs. Efforts should focus on prevention, early diagnosis, and therapy for depression in SCD.