What helps distressed Australian adolescents impacted by cancer? Mechanisms of improvement of the PEER program

PEER is a four-day residential program for adolescents impacted by their own or a relative's cancer, with both psychosocial (acceptance and commitment therapy, self-compassion) and recreational components. This study aimed to determine whether previously observed improvements in quality of life amongst highly distressed participants were mediated by improvements in processes targeted by psychotherapeutic elements of the program (psychological flexibility, mindfulness, self-compassion, peer support, distress). Adolescents attending PEER completed surveys assessing the quality of life and proposed mediator variables at pre-program, post-program and two-month follow-up. Adolescents experiencing high/very high levels of baseline distress (n = 52; 5 patients/survivors, 31 siblings/offspring, 13 bereaved siblings/offspring) were previously identified as experiencing clinically significant improvements in psychosocial well-being; here, mediation analyses explored whether these improvements were associated with improvements in process variables. Findings evidenced improvements in quality of life amongst distressed PEER participants, mediated by increases in psychological flexibility and self-compassion, and reductions in distress. Peer support and mindfulness were not significant mediators. Together, this suggests that the psychosocial benefits of PEER observed for highly distressed adolescents are linked to the specific therapeutic approaches used in the program, rather than being non-specific effects of peer connection or recreation. Findings from this evaluation provide further evidence for the efficacy and mechanisms of the effect of PEER for supporting distressed adolescents impacted by cancer. The study also demonstrates the viability and utility of the therapeutic approaches (acceptance and commitment therapy, self-compassion) used, showing that they have psychosocial benefits for this population.