Chronic Pain, Posttraumatic Stress Disorder, and Opioid Intake: A Systematic Review

Background: The literature suggests that there is a high degree of co-occurrence between chronic pain and posttraumatic stress disorder (PTSD). An association has been found between PTSD and substance abuse. PTSD is a severe disorder that should be taken into account when opioids are prescribed. It has been found that the prevalence of opioid use disorder (OUD) in chronic pain patients is higher among those with PTSD than those without this disorder.

Aim: To perform a systematic review on the association between PTSD, chronic non-cancer pain (CNCP), and opioid intake (., prescription, misuse, and abuse).

Methods: We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The Patient, Intervention, Comparator, and Outcomes (PICOS) criteria were formulated a priori in the protocol of the systematic review. A search was conducted of the PROSPERO database. In March 2019, searches were also conducted of 5 other databases: PubMed, MEDLINE, PsycINFO, Web of Science, and PILOTS. The Scottish Intercollegiate Guidelines Network checklist for cohort studies was used to assess the selected studies for their methodological quality and risk of bias. Each study was evaluated according to its internal validity, participant sampling, confounding variables, and the statistical analysis.

Results: A total of 151 potentially eligible studies were identified of which 17 were retained for analysis. Only 10 met the selection criteria. All the studies were published between 2008 and 2018 and were conducted in the United States. The eligible studies included a total of 1622785 unique participants. Of these, 196516 had comorbid CNCP and PTSD and were consuming opiates. The participants had a cross-study mean age of 35.2 years. The majority of participants were men (81.6%). The most common chronic pain condition was musculoskeletal pain: back pain (47.14% across studies; range: 16%-60.6%), arthritis and joint pain (31.1%; range: 18%-67.5%), and neck pain (28.7%; range: 3.6%-63%). In total, 42.4% of the participants across studies had a diagnosis of PTSD (range: 4.7%-95%). In relation to opioid intake, we identified 2 different outcomes: opioid prescription and OUD. All the studies reported evidence of a greater prevalence of PTSD in CNCP patients who were receiving prescribed opioids and that PTSD was associated with OUD in CNCP patients.

Conclusion: Opioid analgesic prescription as the treatment of choice for CNCP patients should include screening for baseline PTSD to ensure that these drugs are safely consumed.