Your heart beats next to mine: Daily physiological synchrony among black and white ADRD caregiver-care recipient dyads.

Close relationships are often physiologically synchronous, showing correlated changes in cardiovascular reactivity that vary by relationship quality and predict well-being. Little is known about physiological synchrony among dementia caregiver-care recipient dyads, which may be impacted by the chronic strain of caregiving and functional declines due to dementia. The present study examined physiological synchrony among caregivers and care recipients in daily life using heart rate data and whether synchrony varied by interpersonal tensions, relationship type, and race. A total of 148 Alzheimer's disease and related dementia (ADRD) caregivers (ages 22-86; 27% Black; 79% female; 63% spousal caregivers) and their care recipients participated in a 5-day ecological momentary assessment study in which caregivers completed mobile phone surveys every three hours, six times per day, and both caregivers and care recipients wore mobile heart rate monitors 24 h per day. Stability and influence models revealed that caregivers and care recipients were physiologically synchronous in daily life (i.e., past moment heart rate of one dyad member was associated with current moment heart rate of the other dyad member). Physiological synchrony was stronger for spousal and White caregiver dyads, particularly during periods of higher interpersonal tension, whereas Black caregiver dyads exhibited physiological synchrony during periods of lower interpersonal tension. This study adds to the growing literature on physiological synchrony by examining an understudied interpersonal context of dementia caregiving in a diverse sample. Implications of these findings for interventions among ADRD caregiving dyads are discussed.