# Chronic Pain and Posttraumatic Stress Among Patients in Substance Use Treatment: Protocol for NOR-APT, a Longitudinal Cohort Study

## TL;DR

This study explores how chronic pain and PTSD affect substance use treatment outcomes in a large Norwegian cohort over 20 years.

## Contribution

NOR-APT is the first longitudinal study to investigate interactions between SUD, chronic pain, and PTSD in a real-world treatment setting.

## Key findings

- 1645 patients completed questionnaires, with a target sample size of 1400-1500 after data cleaning.
- Registry data linkage is planned for 2026 and 2029/2030 to track long-term outcomes.
- At least 10 publications are planned to explore comorbidities and treatment impacts.

## Abstract

Chronic pain conditions and posttraumatic stress disorder (PTSD) are highly prevalent among patients with substance use disorders (SUDs). Both can impact outcomes of SUD treatment and quality of life. There is a need for a large-scale study on the overlap of and interactions between SUD, chronic pain, and PTSD.

The Norwegian Addiction, Pain and Trauma study (NOR-APT) is the first longitudinal study to describe how substance use and outcomes of SUD treatment are impacted by (1) chronic pain and pain characteristics and (2) interactions between comorbid chronic pain and PTSD.

Self-reported questionnaire data were collected from patients in all types of SUD treatment at four hospital sites in Norway. The questionnaire data on substance use, pain, and posttraumatic stress symptoms will be combined with retrospective and prospective longitudinal data from high-quality demographic and health registries. The registry data cover, for example, treatment episodes, diagnoses, and prescribed medications and socioeconomic variables, with a follow-up period of altogether 20 years (approximately 2008-2029).

Questionnaire data were collected during March 2021-June 2024. Altogether 1890 patients were approached, and 1645 (87%) questionnaires were completed. The estimated final sample size pending data cleaning (eg, removal of duplicates and validation of consent forms) is 1400-1500. Linkage of registry data for approximately 1000 with valid ID numbers and consent is planned for 2026 (retrospective) and 2029/2030 (prospective). At least 10 publications are planned in the period 2025-2028, based on funding received from the Foundation Dam, the Norwegian Research Council, Akershus University Hospital, and Oslo University Hospital. We plan to apply for further funding related to the use of the prospective registry data.

Results from the NOR-APT study will contribute to a better understanding of SUD, chronic pain and PTSD comorbidities, their interactions, trajectories and impact on SUD treatment outcomes, and subjective quality of life. Results can also contribute knowledge toward the development and assessment of treatment interventions that can improve SUD treatment outcomes.

ClinicalTrials.gov NCT04908410; https://clinicaltrials.gov/study/NCT04908410

DERR1-10.2196/67663