Adolescent and young adult (AYA) cancer survivors are at risk for experiencing adverse psychological, social, and behavioral sequelae following treatment. Yet, research on developmentally-appropriate interventions for use with AYA cancer survivors is lacking. The current study sought to address this gap by testing two 4-week, online prosocial writing interventions with AYA cancer survivors. Participants were randomized to one of three conditions—peer helping, expressive writing + peer helping, or a cancer-specific fact-writing control—and completed four writing activities, once per week, each on a different topic. Assessments of the primary (hedonic, eudaimonic social, eudaimonic psychological well-being) and secondary (depressive symptoms, anxiety, physical and behavioral symptoms, social support, positive and negative affect, and fulfillment of psychological needs) outcomes were administered at baseline, weekly, post-intervention, and the 1-month follow-up. In total, 203 participants (Mage = 32.33 years; 76% female) enrolled in the study. Participants were, on average, 5.07 years since diagnosis, and the majority received a diagnosis of thyroid cancer (17%) or breast cancer (15%). Adherence to the intervention was high, and 89% of the sample was retained at post-intervention. Participants in the peer helping condition had significantly greater increases in eudaimonic psychological well-being (b = 1.56, p = .04) from pre- to post-intervention, relative to controls. Both the peer helping and expressive writing + peer helping conditions evidenced a trend towards greater increases in social support (b = 3.47, p = .050 and b = 2.64, p = .077, respectively) from pre- to post-intervention, relative to controls. Effects on well-being were not moderated by psychological distress or prosocial tendencies, two constructs identified by theoretical and empirical literature as potential moderators. Main effects of time were observed across groups for eudaimonic social well-being, depressive symptoms, anxiety, sleep disturbance, fatigue, positive and negative affect, and fulfillment of psychological needs, with all groups showing improvements. A main effect of time on hedonic well-being also emerged, with all three groups reporting declines across the intervention. Prosocial writing-based interventions are promising and warrant further study. Future studies should consider whether the three writing approaches used here are reliably distinct and who benefits most (e.g., moderated effects).
