The impact of adverse childhood experiences on chronic pain, multimorbidity, and analgesia-related outcomes in adulthood

Abstract

Adverse childhood experiences (ACEs) are potentially stressful events or environments that occur before the age of 18 years that have the potential to cause harm or distress, and may undermine an individual’s sense of safety. The World Health Organization states that “to grow and develop optimally, children… must feel safe and secure”, yet estimates suggest that 60% of adults worldwide have experienced at least one ACE. Exposure to ACEs has been linked to a range of negative long-term health outcomes, including higher prevalence of individual long-term conditions (LTCs) like chronic pain. Chronic pain, defined as pain lasting longer than three months, may affect up to 50% of adults and, according to the Global Burden of Disease Study, is the leading cause of years lived with disability worldwide. Much of the research investigating relationships between ACEs and LTCs has considered single conditions in isolation, but in practice many people (37% of the adult population worldwide) live with multiple LTCs, known as multimorbidity. This is especially true of people living with chronic pain. Although there is a large body of evidence on the impact of ACEs on the prevalence of various individual LTCs, it is less clear how ACEs influence multimorbidity. Similarly, the ways in which ACEs shape management choices for chronic pain are less well established. In this thesis I aimed to address these gaps by examining how ACEs affect chronic pain, multimorbidity, and the consequences of processes designed to produce analgesia, a concept I termed analgesia-related outcomes.

This work was co-developed with people who have lived experience of ACEs, chronic pain, and multimorbidity, and it was organised within a single causal framework. It comprised four parts. First, a systematic review with meta-analysis evaluated the relationship between ACEs and multimorbidity in existing studies. Second, a systematic review synthesised the literature linking ACEs with a range of analgesia-related outcomes. Third, an observational analysis in the UK Biobank research cohort examined the relationships between childhood maltreatment and chronic pain, multimorbidity, analgesic use, functioning, substance use disorder, unplanned hospital admissions, and all-cause mortality. Fourth, an observational feasibility study examining the impact of Adverse Childhood Experiences on sensory thresholds in people living with Multimorbidity And/or chronic Pain (the ACE-MAP study) explored whether static and dynamic quantitative sensory testing (QST) can be used to assess, and potentially explain, the impact of ACEs on sensory processing and endogenous analgesic pathways.

Across these strands, higher ACE burden was consistently associated with chronic pain, multimorbidity, greater exposure to analgesic medications, analgesia-related harms, and adverse downstream outcomes. These relationships were dose-dependent and reproducible across instruments and cohorts. The ACE-MAP study demonstrated feasibility and acceptability of a protocol designed to test the relationship between ACEs and QST, but more work is required to understand the impact of ACEs on endogenous pain pathways and the underlying mechanisms. These findings support the need to adopt trauma-informed approaches in healthcare settings, including normalised sensitive enquiry, attention to psychological safety, integration of mental health expertise, and an emphasis on shared decision making. At the population level, they reinforce the case for early prevention and family support to reduce the incidence and impact of ACEs.

Date of Award	2026
Original language	English
Awarding Institution	University of Dundee
Sponsors	Wellcome Trust
Supervisor	Lesley Colvin (Supervisor), Blair Smith (Supervisor), Tim Hales (Supervisor) & Louise Marryat (Supervisor)