BEST FOR CAN - bringing empirically supported treatments to children and adolescents after child abuse and neglect: update to the study protocol.

The implementation trial BESTFORCAN aims to evaluate the dissemination of Trauma-Focused Behavioural Therapy (TF-CBT) for children and adolescents in Germany with posttraumatic stress symptoms (PTSS) after child abuse and neglect (CAN) with a focus on supervision. This update to the study protocol outlines changes made due to practical reasons in the course of the ongoing trial while maintaining methodological quality. The amendments to the original study protocol comprise (1) a more refined operationalisation of the primary outcome sufficiently adherent TF-CBT therapy (SATT), (2) changes in the study sites and (3) additional inclusion of one post-gradual psychotherapy training institute. The adaptions to the original study protocol ensured high methodological quality through the transparent presentation of protocol modification: ensuring the recruitment of participating psychotherapists in training by including a further post-gradual training institute as well as an adaption of the measurement of SATT with high external validity. The objectives, diagnostic set, and secondary outcomes remained unimpaired by the amendment. Therefore, we expect the trial to provide evidence for the effect of model-specific trauma-focused supervision on the implementation outcomes of TF-CBT as compared to supervision as usual. German Clinical Trials Register identifier: DRKS00020516..