Reducing Loneliness Among Older Adults Through Enhancing Positive Affect: A Randomized Controlled Trial With Ecological Momentary Assessments

Loneliness in older adults represents a critical public health challenge, associated with detrimental outcomes including depression, cardiovascular risks, cognitive decline, and elevated mortality. Despite existing interventions, significant gaps persist: most approaches neglect the affective dimension of loneliness, fail to address the core mechanism of perceived discrepancies between expected and actual social relationships, and inadequately account for age-related shifts in socioemotional goals. This randomized controlled trial addresses these limitations by evaluating two theoretically distinct telephone-delivered psychosocial interventions against an active comparator.

The study employs a three-arm design to compare a 4-week Tele-Positive Affect (Tele-PA) intervention grounded in the broaden-and-build theory of positive emotion, which aims at increasing positive affect through eight evidence-based skills (e.g., gratitude, mindfulness, positive reappraisal), and a Tele-Behavioral Activation (Tele-BA) intervention derived from the behavioral explanations of learning theory, focusing on behavior monitoring and strategies, valued activity scheduling, and social skill enhancement. Both are contrasted with Tele-Friendly Visit (FV)-an active control condition comprising matched-frequency neutral conversations devoid of therapeutic components.

Community-dwelling adults aged ≥65 years in Hong Kong with significant loneliness will be randomized to these arms. Using a three-arm, assessor-blinded randomized clinical trial, outcomes will be measured through retrospective surveys and ecological momentary assessments (EMA) at baseline, immediately post-intervention (Week 2), and at 3- and 6-month follow-ups. Primary analyses will examine: 1) the comparative efficacy of Tele-PA and Tele-BA versus the active control in reducing loneliness; 2) differential effectiveness of Tele-PA versus Tele-BA; 3) the mechanisms underlying the effects of Tele-PA and Tele-BA; and 4) the effects of age on the effectiveness.

This research pioneers the integration of affective science with loneliness intervention design while employing EMA to capture mechanistic dynamics. Findings will advance precision approaches for alleviating loneliness in aging populations through scalable, theory-informed strategies.