Manualized Behavioral Activation (BA) protocol delivered via videoconferencing by a trained BA interventionist; 5 sessions over 5 weeks, up to 1-hour in length. The interventionist guides participants in learning BA skills, focusing on strategies to decrease barriers to social connectedness (e.g., limited mobility, inadequate caregiving resources).

Friendly Visitor (FV) calls delivered via videoconferencing by a trained FV interventionist; 5 sessions over 5 weeks, up to 1-hour in length. The interventionist provides social support to participants through good listening and provision of genuine regard.

Five 1-hour sessions of BA delivered by a trained interventionist via video-conferencing

A 10-item self-report questionnaire used to measure an individual's satisfaction with social support using a Likert scale (3-point scale, where anchor labels are specified for each item). This scale consists of two subscales: 4-item social interaction (objective support) scale and 6-item satisfaction with social support (subjective support) subscale. Total scores are calculated by summing responses to items across all items; total scores range 10-30.

An 8-item self-report questionnaire used to measure perceived social isolation using a Likert scale (5-point scale: 'never' = 1 to 'always' = 5). Total raw scores range from 8-40; raw scores are converted to T-scores using an appendix (T-scores are standardized scores that have a mean of 50 and SD of 10). Higher T-score values represent greater perceived social isolation.

A 9-item self-report questionnaire used to measure symptoms of depression. Items are rated using a Likert scale (4-point scale: 'not at all' = 0 to 'nearly every day' = 3). Total scores are calculated by summing responses to items 1-9; total scores range 0-27.

An 11-item self-report questionnaire used to measure intervention acceptability. For this project, reference to "Treatment" will be substituted with "Tele-BA." Items are rated using a 7-point Likert scale. Response values range 1-7 with different verbal anchors for each item. Total scores are calculated by summing responses to items 1-11; total scores range 11-77. The TEI consists of an 8-item General Acceptability subscale and a 3-item Negative Aspects (e.g., discomfort) subscale.