This study proposes a longitudinal study to assess the effects of opioid prescribing practices on outcomes of patients with Alzheimer’s disease and related dementia (ADRD). The research is responsive to priorities espoused by the National Plans to Address Alzheimer’s disease: Goal 2 Enhance Care Quality and Efficiency to address care needs of ADRD patients due to co-occurring chronic conditions. Chronic pain is common in ADRD, with 90% of affected patients relying on pharmacotherapy, such as opioids, to relieve painful symptoms. Use of prescription opioids in ADRD has doubled over the last decade; among users, over half used opioids chronically or concurrently with other central-nervous-system (CNS) depressant medications, contrary to what current pain guidelines suggest. These guidelines, however, adapt evidence primarily from younger populations or older adults with healthy cognition and whether they are suitable for ADRD patients remains unclear. To inform treatment decisions for pain management in ADRD, there is an urgent need for evidence on the clinical effects of existing opioid prescribing practices, considering outcomes aligned with treatment goals. For older adults who suffer from chronic pain, there is a strong need to understand if opioids improve or worsen cognition to help clarify inconclusive findings in the current literature. To fill these research gaps, this proposed study will leverage nationally representative longitudinal survey and assessment data that are linked to Medicare claims to study opioid prescribing practices on outcomes of ADRD patients residing in communities and nursing homes. Specifically, we will examine the associations between the continuation of chronic opioid therapy with outcomes in patients with ADRD and chronic non-cancer pain. We will also evaluate the extent to which concurrent use of opioids with CNS drugs is associated with outcomes in patients with ADRD receiving chronic opioid therapy. Furthermore, we will assess associations between opioid use and changes in cognitive function among non-demented older adults who had moderate or severe pain. We will consider a range of clinical outcomes, including pain intensity, physical and mental health, and safety outcomes, including fall-related injuries, hospitalizations, and opioid use disorder or overdose. Our study will provide empirical evidence on the effects of common opioid prescribing practices on health outcomes pertinent to patients with ADRD and elucidate the role of opioids on cognition in older adults with chronic pain. Because ADRD populations are rarely included in trials, our data will have great potential to further knowledge of the benefits and harms of opioid treatment and inform optimal use and safe opioid prescribing in patients with ADRD. The long-term goal of this line of research is to improve management of chronic pain in older adults, particularly those with cognitive impairment.