PTSD Coach is a mobile mental health app developed by US Veterans Affairs translated into French by Veterans Affairs Canada in partnership with the Department of National Defence and the Canadian Mental Health Association. It was developed for a male population (92% of veterans are men), as is predominantly found in HNC, and addresses the issue of mental health and stigma as found in our HNC patients. PTSD Coach can be used as a stand-alone education and symptom management and contains 4 modules: 1) Learn- Module, 2) Self-Assessment-Module, 3) Manage Symptoms-Module and 4) Find Support-Module. The content of the first and last modules were adapted to the oncological population.

Patients will be assigned to three apps involving playing a game (i.e., Candy Crush, Tetris, or Solitaire), during the waiting time before and between medical treatments in the hospital, on the same weekly schedule as the experimental group. The game apps contain no element of intervention and were selected based on popularity and capacity to interests.

The Otolaryngology - Head and Neck Surgery (OHNS) Departments do not offer systematic interventions on anxiety and self-management, neither does any intervention address stigma. However, participating recruitment centres are already offering a best-of-care approach with well-established psychosocial oncology services, including psychiatrists, psychologists, social workers, nurses, and volunteers. All participants will be free to use hospital- or community-based support throughout the study, which will be tracked in all groups via questionnaire and chart review.

PTSD Coach is a mobile mental health app that addresses the issue of mental health and stigma which can be used as a stand-alone education and symptom management and contains 4 modules: 1) Learn- Module, 2) Self- Assessment-Module, 3) Manage Symptoms-Module and 4) Find Support-Module.

1. Can we recruit a sufficient number (i.e., n=60 over 8 months or 8/month) of newly diagnosed head and neck cancer patients? AND
2. Can we retain a sufficient proportion (i.e., ≥85% at three months post-randomization, having completed the primary outcome) of head and neck patients in all trial arms to allow completion of a full study (n=267) in a timely fashion?

Is the PTSD Coach app acceptable to at least 80% of newly diagnosed head and neck cancer patients, as indicated by 80% positive responses on the Pilot-Study Questionnaire (PSQ; adapted from the CSQ-8; Attkisson & Zwick, 1982)

At least 90% of experimental group complete PTSD Coach within 3 weeks from randomization.

At least 85% of the content for each module of PTSD Coach be completed.

At least 90% of the attention control complete their assigned condition as planned (i.e., 45 min/week over 3 weeks).