4 - (OP1) Cognitive Behavioral Therapy for Loneliness and Social Isolation: A Three-arm Randomized Trial

The COVID-19 pandemic has led to widespread social distancing and quarantine measures, which have intensified social isolation among young adults worldwide. In South Korea, socially isolated young adults have increased rapidly, becoming a major public health and societal concern. Social isolation is linked to various mental and physical health problems, and young adulthood is a key developmental period for building social roles and interpersonal relationships. However, evidence-based interventions targeting socially isolated young adults remain limited.
This study investigated the effectiveness of cognitive behavioral therapy (CBT) for young adults experiencing loneliness and social isolation. A total of 94 socially isolated young adults (mean duration of social isolation = 3 years and 8 months) were randomly assigned to one of three 8-week intervention conditions: (1) face-to-face group CBT (n = 32), (2) face-to-face group behavioral activation (BA; n = 30), or (3) a mobile app–based BA program (n = 32). The group CBT program comprised psychoeducation, self-focused attention training, exposure exercises, self-compassion training, and behavioral activation.
Primary outcomes were loneliness, measured by the UCLA Loneliness Scale, and social isolation, assessed using the Lubben Social Network Scale (LSNS), evaluated at baseline, post-intervention, and 2-month follow-up. Secondary outcomes included depression, anxiety, social anxiety, and behavioral activation. Data were analyzed using an intent-to-treat approach with restricted maximum likelihood estimation.
All three interventions significantly reduced loneliness from baseline to post-intervention and follow-up. Face-to-face group CBT showed the largest reduction in loneliness (p < .001, Cohen’s d = 1.20), followed by face-to-face BA (p = .004, d = 0.71) and app-based BA (p = .028, d = 0.46). A significant increase in social network size was observed only in the face-to-face group CBT condition (p = .006, d = 0.50); though the effect was not maintained at follow-up. For secondary outcomes, significant interaction effects were observed in social anxiety and behavioral activation, but not in depression or general anxiety.
These findings suggest that face-to-face group CBT and BA were more effective in reducing loneliness among socially isolated young adults than mobile BA, with face-to-face group CBT demonstrating the strongest effects. The app-based intervention also demonstrated potential as a scalable, low-intensity approach for addressing loneliness and emotional distress in this population.