Experimental: Therapist-supported internet delivered trauma-focused CBT

Therapist-supported internet delivered trauma-focused CBT. The protocol mirrors the exact content of first-line treatment for children with PTSD but is delivered through a digital platform and will comprise of text-based material as well as audio files and video illustrations in an age-appropriate manner that the participant gains access to sequentially. iTF-CBT will be therapist-assisted, and each participant will have a designated therapist to guide them through treatment. Treatment will span over 12 weeks and integrates cognitive, behavioral, interpersonal, and family therapy principles as well as trauma interventions. Parallel to the child's treatment, the caregivers are provided the same components and parenting practices, and joint child-parent activities are included. Participants will have access to a therapist that will guide them through treatment in a text based format.

Active_comparator: Therapist-supported psychoeducation and stress management

Therapist-supported CBT internet-delivered treatment comprising psychoeducation about PTSD, relaxation/stress management techniques and relapse prevention. The treatment will be delivered in a digital platform for twelve weeks. Participants will have access to a therapist that will guide them through treatment in a text-based material as well as audio files and video illustrations in an age-appropriate manner that the participant gains access to sequentially.