PROJECT SUMMARY/ABSTRACT Language and communication impairments (aphasia) are the defining features of the clinical neurodegenerative dementia syndrome primary progressive aphasia (PPA), which can be caused by Alzheimer’s disease (AD) or frontotemporal lobar degeneration. The devastation of communication negatively impacts quality of life for persons living with PPA and their care partners. Communication difficulties in PPA can also reduce life-space mobility including shrinking social interactions and lowering participation in community activities. Nonpharmacological interventions, including speech-language and psychosocial intervention, may offer significant benefit to the quality of life for persons with PPA and their care partners, but have historically lacked efficacy evidence as well as guidelines to direct best clinical care practices. We have been changing this landscape, through the development of the Communication Bridge (CB) intervention with strategically staged, rigorous clinical trials that are on a path towards implementation. The CB1 trial established feasibility of delivering our intervention at a global scale via telepractice and demonstrated gains in functional communication outcomes that were maintained 6-months post baseline. Next, the CB2 trial provided the first rigorous Phase 2a, Stage II, superiority, randomized controlled trial (RCT) of speech-language intervention in PPA. CB2 interim analysis conditional power results suggest a high probability of trial success (>80%) but also identified a need for greater psychosocial education and counseling. Thus, the current application proposes the CB3 trial designed to optimize the intervention by testing whether the addition of psychosocial education and counselling (PEC) to speech-language intervention (Experimental arm) is superior to an active Control intervention. The RCT will be complemented by Aim 1a, which will maximize pragmatic trial readiness following the Readiness Assessment for Pragmatic Trials (RAPT) tool; and Aim 2, which will assess functional outcomes with novel wearable sensors to objectively measure life participation using a ‘Life-Space Mobility’ framework. Trial outcomes will inform future pragmatic trial design. The translational potential is high since the delivery model and primary outcomes are aligned with current clinical practice. In the absence of a definitive cure for AD and related neurodegenerative diseases, it is important to identify and evaluate strategies that help individuals maximize their quality of life, and this project will help fulfill this need.