BACKGROUND: Approximately 10% of young people 'often' feel lonely, with loneliness being predictive of multiple physical and mental health problems. Research has found CBT to be effective for reducing loneliness in adults, but interventions for young people who report loneliness as their primary difficulty are lacking.

METHOD: CBT for Chronic Loneliness in Young People was developed as a modular intervention. This was evaluated in a single-case experimental design (SCED) with seven participants aged 11-18 years. The primary outcome was self-reported loneliness on the Three-Item Loneliness Scale. Secondary outcomes were self-reported loneliness on the UCLA-LS-3, and self- and parent-reported RCADS and SDQ impact scores. Feasibility and participant satisfaction were also assessed.

RESULTS: At post-intervention, there was a 66.41% reduction in loneliness, with all seven participants reporting a significant reduction on the primary outcome measure (p < .001). There was also a reduction on the UCLA-LS-3 of a large effect (d = 1.53). Reductions of a large effect size were also found for parent-reported total RCADS (d = 2.19) and SDQ impact scores (d = 2.15) and self-reported total RCADS scores (d = 1.81), with a small reduction in self-reported SDQ impact scores (d = 0.41). Participants reported high levels of satisfaction, with the protocol being feasible and acceptable.

CONCLUSIONS: We conclude that CBT for Chronic Loneliness in Young People may be an effective intervention for reducing loneliness and co-occurring mental health difficulties in young people. The intervention should now be evaluated further through a randomised controlled trial (RCT).