A randomized controlled trial testing theory-driven enhancements to increase the efficacy of and engagement in a brief cognitive-behavioural therapy text-message intervention for co-occurring posttraumatic stress disorder symptoms and alcohol misuse.

This study will identify the simplest, most efficacious CBT intervention for PTSD + AM. Its use of cognitive and social psychology-based enhancement and of a factorial decision can serve as examples of how to enhance and increase engagement in brief, self-directed CBT interventions.