The effect of social skills training on loneliness among adolescent girls in Iran: a randomized controlled trial

Adolescence is a critical developmental period marked by a heightened vulnerability to loneliness, a subjective distress linked to anxiety and depression. Evidence for interventions is particularly limited in low- and middle-income countries. This study evaluated the effect of a brief, group-based social skills training program on loneliness, depression, and anxiety among adolescent girls in Tehran, Iran. A randomized controlled trial was conducted with 100 girls aged 12-14, randomly allocated to an intervention group (n = 50) or a no-intervention control group (n = 50). The intervention consisted of three 4-hour recreational-educational sessions delivered over consecutive days. The primary outcome was loneliness, measured using the UCLA Loneliness Scale. Secondary outcomes were depression (Beck Depression Inventory) and anxiety (Beck Anxiety Inventory), assessed at baseline and 8-week follow-up. Data were analyzed using analysis of covariance (ANCOVA) adjusting for baseline scores, with an intention-to-treat approach and no attrition. While both groups demonstrated significant within-group reductions in loneliness, anxiety, and depression over time (all p < 0.01), ANCOVA revealed no statistically significant between-group differences at post-intervention for loneliness (F = 3.255, p = 0.074, partial η² = 0.032), anxiety (F = 0.470, p = 0.495, partial η² = 0.005), or depression (F = 0.723, p = 0.397, partial η² = 0.007). The brief social skills training did not demonstrate statistically significant superiority over the control condition in reducing loneliness, anxiety, or depression. Future interventions may require a longer duration or different components to achieve a significant comparative benefit.