The aim of this project is to look at emotional regulation in people with posttraumatic stress disorder (PTSD) and substance use disorder (SUD). This study will explore how people with PTSD-SUD regulate their emotions and how this might explain the relationship between these two disorders. In turn, this may inform effective treatment strategies for people with comorbid PTSD-SUD.

Emotional regulation refers to the way in which people process and respond to their emotions. PTSD and SUD commonly cooccur and this is associated with adverse outcomes including high rates of relapse, overdose, and suicide. We therefore need effective treatments to address this clinical concern. Evidence suggests emotional regulation might be important in the development and maintenance of PTSD and SUD and therefore it might be a useful target for treatment. However, most research in this area has been quantitative and has not considered how gender, social circumstances and trauma or substance type might affect the way people regulate their emotions. This study will recruit 40 adults with trauma histories and PTSD who are currently receiving treatment in a community drug and alcohol service for their substance use. Participants will be interviewed to explore how they regulate their emotions and how this relates to their social circumstances. This study will also explore whether gender, substance or trauma type affect the way people regulate their emotions. We hope this will help to improve treatment for people with PTSD and SUD.

Inclusion Criteria:

• • Adults aged 18+

  • Receiving treatment from a community substance use service at the time of the study.
  • Experienced, witnessed or been confronted with at least one traumatic event (according to PTSD Diagnostic Scale for DSM-5) (PDS-5) (Foa, 2016).
  • Participant endorses at least 3 PTSD symptoms from criterion B-E, measured using the PDS-5.
  • Able to communicate and understand English sufficiently to engage in a qualitative interview.

Exclusion Criteria:

• • Staff recommend the individual should not take part in the study

  • The individual is unable to provide informed consent

A sample of approximately 40 people with posttraumatic stress disorder who are accessing substance use services in the community will be recruited and interviewed.

Individual participant data (IPD) will not be made available to other researchers.