Literary Review of The Pain / Trauma / Addiction Mechanism

Chronic Pain, Trauma, and Addiction: A Review of the Literature

Chronic pain, trauma exposure, and addiction frequently co-occur and are best understood as interconnected phenomena rather than isolated clinical problems. Chronic pain affects approximately 20% of U.S. adults, with nearly 7% experiencing high-impact chronic pain that limits daily activities [1]. Pain is not purely a nociceptive event; it is shaped by biologic, psychological, and social factors, and often coexists with mental health and substance use disorders [2]. Persistent pain itself may evolve into a disease state, characterized by neurobiological, cognitive, and social changes that extend beyond the original tissue injury [3].

Addiction, particularly opioid use disorder, is also influenced by biological vulnerability, psychological distress, and social context. The American Society of Addiction Medicine describes addiction as involving biological, psychological, social, and spiritual dimensions, with relapse often triggered by environmental cues and emotional stressors [4]. In patients with chronic pain, the risk of substance use disorder is not solely determined by medication exposure; lifelong risk factors, including early-life adversity, contribute to vulnerability [5].

Increasingly, research supports the role of early adversity as a shared upstream determinant of chronic pain, mental illness, and substance use.

Adverse Childhood Experiences (ACEs)

Adverse childhood experiences (ACEs) refer to potentially traumatic events occurring before age 18, including abuse, neglect, and household dysfunction. The original ACE framework included 10 categories: emotional, physical, and sexual abuse; emotional and physical neglect; and household challenges such as parental substance use, mental illness, incarceration, domestic violence, and parental separation or divorce [6].

ACEs are common. National survey data indicate that approximately 63.9% of U.S. adults report at least one ACE, and 17.3% report four or more [7]. Exposure is socially patterned, with higher prevalence among individuals with lower income, lower educational attainment, and certain racial and ethnic groups [8].

A substantial body of evidence demonstrates a dose–response relationship between cumulative ACE exposure and adverse adult outcomes. A meta-analysis in The Lancet Public Health found that individuals with four or more ACEs had markedly increased odds of substance misuse, interpersonal violence, mental illness, and several chronic medical conditions compared with those with none [9]. Additional meta-analytic evidence shows a significant dose-dependent relationship between ACEs and multimorbidity in adulthood, with each additional ACE increasing the odds of multimorbidity by approximately 13% [10].

ACEs have also been associated specifically with substance use disorder and overdose risk [11], as well as with chronic pain conditions such as primary headache disorders, again demonstrating dose–response patterns [12].

Importantly, ACEs are associated not only with psychosocial outcomes but also with measurable biological effects. Prolonged activation of stress response systems—sometimes referred to as “toxic stress”—can disrupt neurodevelopment, endocrine regulation, and immune function, increasing lifelong risk for physical and mental illness [13].

Social Determinants of Health

Chronic pain and addiction are also influenced by social determinants of health (SDOH), defined as the conditions in which people are born, grow, live, work, and age [14]. These include economic stability, education, neighborhood environment, healthcare access, and social context.

Chronic pain prevalence varies across demographic and socioeconomic groups. Recent national data show higher rates of chronic pain among certain marginalized populations, including American Indian/Alaska Native adults and individuals experiencing social disadvantage [1]. Broader reviews demonstrate that disadvantaged social groups consistently experience worse pain outcomes, although the mechanisms are multifactorial and incompletely understood [15].

Among patients with chronic pain, social disadvantage is also associated with higher odds of opioid use disorder. In a large multi-institutional dataset, higher area deprivation, unemployment, delayed medical care, and inability to afford care were all independently associated with increased odds of opioid use disorder in individuals with chronic pain [16].

ACEs and SDOH are related but distinct constructs. Lower childhood socioeconomic position is strongly associated with increased exposure to ACEs [17]. Thus, early adversity and social disadvantage often cluster, compounding risk across the life course.

Trauma as a Cross-Cutting Mechanism

Trauma can be conceptualized across multiple domains: psychological (e.g., psychiatric illness), physical (e.g., injury, abuse), social (e.g., chronic instability, poverty), and relational. Trauma-informed frameworks emphasize that early and repeated adversity can alter stress physiology and coping patterns, increasing vulnerability to chronic disease and maladaptive coping behaviors [18].

The relationship between ACEs and addiction illustrates this interaction. Individuals with higher ACE scores are at significantly increased risk for substance use disorders and overdose [11]. Similarly, ACE exposure is associated with poorer analgesia-related outcomes, including greater risk of substance misuse and overdose among adults receiving pain treatment [19].

These findings suggest that trauma exposure may shape both pain perception and the risks associated with its treatment.

Implications for Treatment

Given the multifactorial nature of chronic pain and addiction, major guidelines emphasize multimodal and individualized care. The CDC Clinical Practice Guideline for Prescribing Opioids for Pain highlights the complexity of pain and the importance of integrating nonpharmacologic therapies, behavioral health assessment, and careful risk stratification [2].

Psychological therapies are supported by evidence in chronic musculoskeletal pain, reflecting the recognized role of psychosocial factors in pain experience and outcomes [20]. For opioid use disorder, medication-assisted treatment (e.g., buprenorphine, methadone) remains a cornerstone of care, combined with behavioral and psychosocial interventions [4].

There is growing interest in trauma-informed care models, which aim to recognize and respond to the impact of trauma without necessarily relying on formal ACE score–based screening. The American College of Preventive Medicine has recommended population-level ACE surveillance and trauma-informed approaches, while cautioning against routine individual ACE score screening in the absence of clear evidence of benefit [21].

In clinical practice, this translates to sensitive trauma inquiry within therapeutic relationships, attention to co-occurring mental health and substance use disorders, and coordination with community resources.

Conclusion

Chronic pain, trauma exposure, and addiction frequently intersect through shared biological, psychological, and social pathways. Adverse childhood experiences and social determinants of health contribute to risk in a graded, dose-dependent fashion across the life course. Evidence supports a biopsychosocial model of care that integrates medical, behavioral, and social interventions.

While no single framework fully explains the complexity of these conditions, an integrated approach—grounded in epidemiologic evidence, trauma-informed principles, and multimodal treatment—offers a coherent strategy for addressing the pain–trauma–addiction nexus in contemporary practice.

Sources:

Chronic pain among adults-United States, 2019 – 2021. MMWR: Morbidity and Mortality Weekly Report, 2023
CDC clinical practice guideline for prescribing opioids for pain-United States, 2022. MMWR: Recommendations and Reports, 2022
Persistent pain as a disease entity: implications for clinical management. Anesthesia and Analgesia, 2004
The ASAM national practice guideline for the treatment of opioid use disorder: 2020 focused update. Journal of Addiction Medicine, 2020
Pain management best practice inter-agency task force report. United States Department of Health and Human Services, 2019
Preventing childhood toxic stress: partnering with families and communities to promote relational health. Pediatrics, 2021
Prevalence of adverse childhood experiences among U.S. adults-behavioral risk factor surveillance system, 2011 – 2020. MMWR: Morbidity and Mortality Weekly Report, 2023
Prevalence of adverse childhood experiences from the 2011-2014 behavioral risk factor surveillance system in 23 states. JAMA Pediatrics, 2018
The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis. The Lancet: Public Health, 2017
The impact of adverse childhood experiences on multimorbidity: a systematic review and meta-analysis. BMC Medicine, 2024
Adverse childhood experiences are associated with history of overdose among patients presenting for outpatient addiction care. Journal of Addiction Medicine, 2023
Adverse childhood experiences and primary headache disorders: a systematic review, meta-analysis, and application of a biological theory. Neurology, 2023
Adversity in childhood is linked to mental and physical health throughout life. BMJ, 2020
Social determinants of health and obstetric outcomes: a report and recommendations of the workshop of the Society for Maternal-fetal Medicine. American Journal of Obstetrics and Gynecology, 2024
Over 50 years of research on social disparities in pain and pain treatment: a scoping review of reviews. Pain, 2025
Associations between social determinants of health and opioid-use disorder among chronic pain patients from a multi-institutional dataset. Anesthesia and Analgesia, 2025
Relationship between childhood socioeconomic position and adverse childhood experiences (ACEs): a systematic review. Journal of Epidemiology and Community Health, 2019
Trauma-informed care. Pediatrics, 2021
Impact of adverse childhood experiences on analgesia-related outcomes: a systematic review. British Journal of Anaesthesia, 2025
APA clinical practice guideline for psychological and other nonpharmacological treatment of chronic musculoskeletal pain in adults. American Psychological Association, 2024
Recommendations for population-based applications of the adverse childhood experiences study: position statement by the American College of Preventive Medicine. AJPM Focus, 2022