This study is enrolling participants who are already implanted with a S-ICD device (Subcutaneous Implantable Cardioverter Defibrillator, which is a device designed to monitor heart rhythms and deliver a shock to the heart to stop life threatening heart rhythms), and are undergoing a routine outpatient clinic follow up appointment to have their S-ICD checked. The aim of the study is to see if a feature in the device can recognize muscle movement and differentiate movement from irregular heart signals. The study involves doing some simple arm exercises while collecting device data, both with this feature turn on and then with it turned off. Participants will be randomized to either have the feature turned on or off initially then it will be programmed the alternative way and the same exercise testing will be repeated. The study will involve just one visit.

Written Exposure Therapy (WET) is a five-session mental health therapy for post-traumatic stress disorder (PTSD). Research shows that it works as well as longer treatments for PTSD among people over 18, even though it requires fewer sessions than other PTSD therapies. However, WET has not been adapted and formally tested in individual therapy with people aged 12 to 18. Our study aims to see how WET can be adapted to meet the needs of people aged 12 to 18 who have experienced trauma and currently have PTSD symptoms. To adapt WET for this age group, first we will talk with PTSD experts and people aged 12 to 18 to learn what changes might make WET more suitable for young people. We'll also deliver WET to five people aged 12 to 18 following the manual as it is written for people over age 18 to see what needs adjusting.

In the next part of the study, we will recruit 48 adolescents aged 12 to 18 in a pediatric primary clinic who have symptoms of PTSD and randomize them to either receive the adapted version of WET or to receive gold-standard PTSD treatment: Trauma-Focused Cognitive Behavior Therapy. If assigned to receive adapted WET, participants will take part in five to seven weekly therapy sessions and five study visits (before therapy, and 6-week, 10-week, 20-weeks, and 30 weeks after starting the therapy). If assigned to receive TF-CBT, participants will take part in 12 to 16 weekly therapy sessions and five study visits (before therapy, and 6-week, 10-week, 20-weeks, and 30-weeks after starting the therapy). The purpose of the study visits for a 30-week time period is to better understand who they are as a person and their current mental health symptoms and diagnoses. All therapy and study visits can be completed remotely or in person, per your preference. Individuals who are 18 can participate without caregiver permission; individuals aged 12 to 17 can only participate with caregiver permission. Our goal is to find the best way to provide effective PTSD treatment for young people that can be delivered in real-world pediatric primary care settings, so that ultimately more people can get the help they need after traumatic experiences.