Alzheimer's disease and related dementias (ADRD) are chronically underdiagnosed in the U.S., particularly among minoritized racial and ethnic groups. Primary care providers are at the forefront of diagnosis given the increasing prevalence of cases and shortage of dementia specialists. Advances in policy, detection, and treatment in the past decade necessitate an updated review of the current state of determinants of ADRD diagnosis in U.S. primary care settings.

Following Joanna Briggs Institute guidelines, we conducted a scoping literature review on ADRD diagnosis among older adults in U.S. primary care settings. Studies published in English from January 2010 to January 2024 were retrieved from PubMed, PsycINFO, and CINAHL. We extracted primary data on study characteristics and synthesized key findings according to facilitators, barriers, and rates of diagnosis in primary care.

Of 563 articles retrieved, 12 met eligibility criteria. Three studies reported rates of diagnosis, and all but one reported facilitators and/or barriers to diagnosis. ADRD remains underdiagnosed in primary care settings, especially in the earliest symptomatic stage (i.e., mild cognitive impairment). Multi-level barriers and facilitators were identified including individual beliefs about ADRD (e.g., value of early diagnosis), interpersonal relationships between patients and their family members and providers (e.g., importance of an established clinical relationship), and healthcare system limitations (e.g., insufficient resources and training).

Despite national policy efforts to improve timely diagnosis of ADRD, underdiagnosis remains a clinical and public health challenge. Increased attention to social and community contexts will be important for future research and intervention.