Influence of implementation fidelity on the effectiveness of a T-CBT program targeting emotional problems in childhood

Abstract Super Skills for Life (SSL) is a transdiagnostic program targeting children with internalizing problems. This study aimed to evaluate: 1) The Spanish SSL program's fidelity level; 2) the relationship between the implementation fidelity dimensions; 3) outcomes at posttest and 12-month follow-up depending on implementation fidelity; 4) mediation effects of self-concept dimensions to reduce internalizing and externalizing problems at follow-up. Participants were 119 schoolchildren aged 8–12. Two groups were established: high (HFG) and low fidelity (LFG). At posttest, HFG presented lower depression, anxiety, total difficulties, and externalizing symptoms, and higher academic and family self-concept than LFG. At follow-up, LFG presented higher depression, total difficulties, and internalizing symptoms, and lower academic, social, and family self-concept. All posttest self-concept dimensions had a significant impact at follow-up on internalizing symptoms. Academic, social and physical self-concept dimensions impacted externalizing symptoms. Thus, although SSL program is effective for treating emotional symptoms even with low implementation fidelity, it is more effective with high implementation loyalty.