PROJECT SUMMARY / ABSTRACT Early intervention for young adults experiencing early psychosis significantly improves long-term functional trajectory. However, a long duration of untreated illness significantly reduces the impact of treatment. Caregivers often play a pivotal role in treatment-seeking, making first contact with providers, persuading the affected relative to make such contacts, or ensuring that the affected individual remains engaged in care. However, caregivers often lack accurate information about psychosis, treatments and recovery, or feel overwhelmed and unable to help or communicate with their affected relative. During this period, they are especially vulnerable to problematic or counterproductive appraisals of illness, for example, catastrophizing beliefs, or self- or patient-blaming attributions. The cognitive model of caregiving argues that negative family interactions can worsen symptoms and functioning while impeding help-seeking. Specialized family interventions improve outcomes for caregivers and affected young adults, but these interventions are provided to EP families in which the affected young adult has already presented to treatment. Thus, caregivers of untreated young adults with EP – arguably the individuals at greatest risk for poor outcomes – lack access to the services they need. Caregivers often turn to online resources for more information and social support. Early work examining web-based platforms has demonstrated that digital health technologies are feasible, acceptable, and have potential to improve caregivers’ psychosis-related knowledge and appraisals. Mobile health interventions are particularly well-suited to this task, as they can provide individualized, real-time, real- place support. It remains unclear at present, however, whether and how remotely delivered mHealth can be leveraged to increase engagement in treatment for young adults with EP. The proposed research project aims to develop and test an mHealth intervention designed to improve caregivers’ illness knowledge and caregiving skills through interactive cognitive-behavioral modules, and through these improvements, reduce distress, improve coping, improve family communication, increase caregiver treatment facilitation and reduce duration of untreated psychosis. This proposal will involve (1) needs assessment and user co-design sessions with EP caregivers to understand their needs, interests and preferences in a caregiver-facing mHealth intervention, (2) a one-week usability field trial of this new intervention to determine feasibility and functionality, and (3) a remote pilot randomized controlled trial comparing this new intervention to existing online caregiving support resources. Analyses will determine whether this approach is acceptable and feasible, as well as explore its effectiveness and impact on key components of the cognitive model of caregiving.