Duloxetine Plus Exercise to Improve Physical Function in Veterans With Knee Osteoarthritis, Pain, and Psychological Comorbidity

Knee osteoarthritis (KOA) and depressive symptoms are both common among older adults and Veterans and are major contributors to chronic pain, reduced mobility, declines in physical function, disability, and poorer overall health outcomes. Veterans with KOA frequently experience co-occurring depressive symptoms, which can worsen pain, interfere with rehabilitation, and reduce adherence to exercise and other self-management strategies. Existing VA care guidelines generally treat KOA and depressive symptoms separately, and there remains limited evidence supporting integrated interventions that target both conditions simultaneously while also improving physical function.

Current knowledge gaps include how to optimize adherence to aerobic exercise among individuals with pain and depressive symptoms and whether combining pharmacologic and rehabilitative approaches provides greater benefit than usual care alone. Aerobic exercise is a recommended first-line treatment for KOA and can improve both mood and physical function, but sustained participation is often difficult in individuals with chronic pain and depressive symptoms. Similarly, duloxetine has demonstrated benefits for both depressive symptoms and KOA-related pain, although interventions targeting only one condition have generally produced limited effects.

Preliminary work conducted by the study team demonstrated that combining duloxetine with a hybrid supervised aerobic exercise program that included both center-based and home-based walking components was feasible and acceptable among individuals with symptomatic KOA and depressive symptoms. Participants experienced clinically meaningful improvements in pain, activities of daily living, walking ability, endurance, psychological symptoms, self-efficacy, and willingness to engage in pain self-management strategies. These findings support the rationale for the proposed study and the evaluation of a complementary care model integrating pharmacologic and non-pharmacologic treatments for Veterans with KOA and depressive symptoms. This study is a Phase II, three-arm, randomized clinical trial designed to evaluate the efficacy of a hybrid supervised aerobic exercise program combined with duloxetine among Veterans with symptomatic knee osteoarthritis and depressive symptoms.