ABSTRACTMany breast cancer survivors (estimated 70% in some studies) experience clinically significant depressionand/or anxiety (together psychological distress hereafter distress) in the months and years after finishing cancertreatments. To address this important need meditation interventions have been developed to reduce distressfor breast cancer survivors while also improving (or stabilizing) objective indicators of stress physiology (i.e.diurnal cortisol rhythm; DCR). In the last several years progress has been made to deliver these meditationinterventions through digital technology to improve scalability and accessibility (i.e. online and/or through apps)to reduce distress experienced by survivors. Online meditation interventions are especially important becausethey ensure ongoing viability of a popular integrative modality for many survivors who are unable to engage inface-to-face supportive care activities outside the home. Despite progress existing online meditationinterventions have several limitations that undercut their effectiveness to reduce survivor distress. Onlinemeditation interventions have: 1) centered mostly on mindfulness which does not actively work to cultivateprosocial and interpersonal relationship capacity and provides limited contemplative skills for survivors who maysuffer from feelings of social isolation that contribute to distress; 2) often been asynchronous with no directinterventionist contact over the course of meditation training; and 3) have often not included survivors' informalcaregivers (i.e. adult family members who live with and typically provide half the care for survivors). Thisresearch will address these limitations. We will build on the rigor of prior research to reduce survivor distresswith a compassion meditation intervention called CBCT (Cognitively-Based Compassion Training) for onlinesynchronous delivery by trained interventionists that is also inclusive of caregivers. CBCT is an 8-weekintervention that starts with attention and mindfulness but then builds to contemplation about compassion for theself and others and is different from other meditation interventions (i.e. mindfulness meditation). The goal ofCBCT is to directly enhance feelings of social connection equanimity and self-compassion and reduce negativeaffect and through these pathways lessen distress. We seek to determine if CBCT reduces distress andimproves DCR for survivors compared to an active attention control (Health Education HE) when deliveredremotely by Zoom to both survivors and caregivers as a dyad (i.e. CBCT for dyads; CBCT-D). We will also testwhether or not including caregivers in CBCT-D reduces distress and optimizes DCR more than when survivorsreceive CBCT by themselves alone (i.e. CBCT for survivors; CBCT-S). If successful this research will provideevidence regarding efficacy of an online synchronous dyadic CBCT intervention and the extent to which itdoes so through the mediational pathway of social connection with caregivers. This research will fill an importantgap in evidence for interventions that can reduce distress an NCI priority for the growing numbers of survivorsand caregivers.