JMIR Publications

ABSTRACT

Background:

Loneliness, or perceived social isolation, is prevalent in both the general population and clinical practice. Although loneliness has repeatedly been associated with mental and physical health, research on interventions that reduce loneliness effectively is still rather scarce.

Objective:

This study aims to evaluate the efficacy of a guided and an unguided version of the same internet-based cognitive behavioral self-help program for loneliness (SOLUS-D) for adults.

Methods:

A total of 250 participants will be randomly assigned to either of two intervention groups (SOLUS-D with guidance or SOLUS-D without guidance) or a waitlist control group (2:2:1 allocation ratio). Adult participants suffering from high levels of loneliness will be recruited from the general population. Individuals with current severe depression or ongoing severe substance use disorder, previous or current bipolar or psychotic disorder, or acute suicidality will be excluded from the trial. Assessments take place at baseline, 5 (mid-treatment) and 10 weeks (post-treatment). The primary outcome is loneliness assessed with the 9-item UCLA Loneliness Scale at post-treatment. Secondary outcomes include depressive symptoms, symptoms of social anxiety, satisfaction with life, social network size, and variables assessing cognitive bias and social behavior. The maintenance of potentially achieved gains will be assessed and compared at 6 and 12 months after randomization in the two active conditions. Potential moderators and mediators will be tested exploratorily. Data will be analyzed on an intention-to-treat basis.

Results:

Recruitment and data collection started in May 2021 and is expected to be completed by 2022, with the 12-month follow-ups to be completed by 2023. As of the submission of the manuscript, 134 participants are randomized.

Conclusions:

This three-arm randomized controlled trial will add to existing research on the efficacy of loneliness interventions. Furthermore, it will shed light on the role of human guidance in internet-based treatments for lonely individuals and possible mechanisms of change. If SOLUS-D proves effective, it could provide a low-threshold, cost-efficient way to help and support lonely individuals. Clinical Trial: The trial was registered on December 7, 2020, at ClinicalTrials.gov NCT04655196; https://clinicaltrials.gov/ct2/show/NCT04655196. In case of important protocol modifications, trial registration will be updated.