Inequality and intergenerational transmission of complex adversity
Authors: Stuart A Kinner, Rohan Borschmann
Journal: The Lancet Public Health (2017)

Young people exposed to adversity often have poor health outcomes in adulthood. A large body of evidence links adverse childhood experiences (ACEs) with impaired health and social functioning in later life in a dose-response fashion, which is suggestive of a causal relationship.1Anda RF Felitti VJ Bremner JD et al.The enduring effects of abuse and related adverse experiences in childhood: a convergence of evidence from neurobiology and epidemiology.Eur Arch Psychiatry Clin Neurosci. 2006; 256: 174-186Crossref PubMed Scopus (2635) Google Scholar, 2Felitti VJ Anda RF Nordenberg D et al.Relationship of childhood abuse and household dysfunction to many of the leading causes of death in adults.Am J Prevent Med. 1998; 14: 245-258Summary Full Text Full Text PDF PubMed Scopus (9643) Google Scholar Minimisation of exposure to early adversity and building of resilience in the face of such adversity are important to reduction of the burden of disease, improvement of public health, and reduction of health inequalities. In their systematic review and meta-analysis of the ACE literature in The Lancet Public Health, Karen Hughes and colleagues3Hughes K Bellis MA Hardcastle KA et al.The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis.Lancet Public Health. 2017; 2: e356-e366Summary Full Text Full Text PDF Scopus (1762) Google Scholar highlight the diversity of poor health outcomes associated with childhood adversity: exposure to at least four ACEs was associated with increased odds of poor mental, physical, and sexual health; harmful substance use; violence (perpetration and victimisation); and physical inactivity. The effects of early adverse life experiences on subsequent health trajectories are evidently profound and diffuse. Just as ACE exposures tend to cluster together within disadvantaged individuals and communities,4Braveman P Barclay C Health disparities beginning in childhood: a life-course perspective.Pediatrics. 2009; 124: S163Crossref PubMed Scopus (375) Google Scholar so too do the poor health outcomes associated with these exposures. Both the social gradient in health and the concentration of the burden of disease in disadvantaged populations are well documented.5Marmot M Friel S Bell R Houweling TA Taylor S Closing the gap in a generation: health equity through action on the social determinants of health.Lancet. 2008; 372: 1661-1669Summary Full Text Full Text PDF PubMed Scopus (2116) Google Scholar, 6Ljung R Peterson S Hallqvist J Heimerson I Diderichsen F Socioeconomic differences in the burden of disease in Sweden.Bull World Health Organ. 2005; 83: 92-99PubMed Google Scholar One particularly striking finding from Hughes and colleagues3Hughes K Bellis MA Hardcastle KA et al.The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis.Lancet Public Health. 2017; 2: e356-e366Summary Full Text Full Text PDF Scopus (1762) Google Scholar is the association between multiple ACE exposures and subsequent suicide attempts (odds ratio [OR] 30·14 [95% CI 14·73–61·67]). The association between ACE exposure and self-harm—which is more prevalent than and is strongly associated with subsequent suicide7Herbert A Gilbert R Cottrell D Li L Causes of death up to 10 years after admissions to hospitals for self-inflicted, drug-related or alcohol-related, or violent injury during adolescence: a retrospective, nationwide, cohort study.Lancet. 2017; (published online May 25.)http://dx.doi.org/10.1016/S0140-6736(17)31045-0Summary Full Text Full Text PDF PubMed Scopus (40) Google Scholar—was not examined. Also remarkable was the consistent association between ACE exposure and poor health outcomes across settings and populations, despite marked heterogeneity in exposure definition and outcome measurement. Although most of the included studies measured a core set of ACEs, what the so-called core ACEs are is debated in the literature,8Finkelhor D Shattuck A Turner H Hamby S Improving the adverse childhood experiences study scale.JAMA Pediatrics. 2013; 167: 70-75Crossref PubMed Scopus (331) Google Scholar and the included studies also measured various other ACEs. The consistent association between exposure to at least four ACEs (versus none) and poor health outcomes, irrespective of the particular combination of ACEs, points towards a causal pathway defined by cumulative exposure to stress, trauma, and adversity, rather than specific effects of exposure to particular individual adversities.1Anda RF Felitti VJ Bremner JD et al.The enduring effects of abuse and related adverse experiences in childhood: a convergence of evidence from neurobiology and epidemiology.Eur Arch Psychiatry Clin Neurosci. 2006; 256: 174-186Crossref PubMed Scopus (2635) Google Scholar Hughes and colleagues3Hughes K Bellis MA Hardcastle KA et al.The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis.Lancet Public Health. 2017; 2: e356-e366Summary Full Text Full Text PDF Scopus (1762) Google Scholar also point out that the health outcomes most strongly associated with multiple ACE exposure—such as problematic substance use—themselves potentially represent ACEs for the next generation. This finding further strengthens the case for upstream public health approaches, particularly in disadvantaged populations in which the prevalence of both ACE exposure and poor health outcomes are comparatively high. Effective responses to ACEs have the potential to improve the health of young people now, their health in later life, and health outcomes for their children—a compounding benefit described in the Lancet Commission on adolescent health and wellbeing9Patton GC Sawyer SM Santelli JS et al.Our future: a Lancet commission on adolescent health and wellbeing.Lancet. 2016; 387: 2423-2478Summary Full Text Full Text PDF PubMed Scopus (1511) Google Scholar as the "triple dividend". Translation of these important findings into improved public health outcomes is complicated by some limitations of the literature on which this systematic review and meta-analysis3Hughes K Bellis MA Hardcastle KA et al.The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis.Lancet Public Health. 2017; 2: e356-e366Summary Full Text Full Text PDF Scopus (1762) Google Scholar is based. First, the epidemiology of ACE exposure at the population level is poorly understood. Although estimates have been made of the burden of child maltreatment in some high-income countries,10Gilbert R Widom CS Browne K Fergusson D Webb E Janson S Burden and consequences of child maltreatment in high-income countries.Lancet. 2009; 373: 68-81Summary Full Text Full Text PDF PubMed Scopus (2461) Google Scholar little is known about the prevalence of exposure to other ACEs, which ACEs tend to co-occur, or the epidemiology of ACE exposure in low-income and middle-income countries. Among the included studies, 57% of participants were exposed to at least one measured ACE, such that ACE exposure appears normative. This finding raises questions about the ecological validity of treatment of no ACE exposure as the reference category in analyses. Second, interpretation of the ACE literature is complicated by marked heterogeneity in the category of exposure to at least four ACEs. In a study9Patton GC Sawyer SM Santelli JS et al.Our future: a Lancet commission on adolescent health and wellbeing.Lancet. 2016; 387: 2423-2478Summary Full Text Full Text PDF PubMed Scopus (1511) Google Scholar measuring nine ACEs (the mean number in the studies included by Hughes and colleagues3Hughes K Bellis MA Hardcastle KA et al.The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis.Lancet Public Health. 2017; 2: e356-e366Summary Full Text Full Text PDF Scopus (1762) Google Scholar), 382 possible combinations of ACE exposure exist that would produce an ACE score of at least four. ACE exposures could have been acute or chronic, and could vary in intensity. Although the ACE literature by definition focuses on childhood, most of the included studies counted exposures from birth up to age 16 years or 18 years—that is, including early (10–14 years) and late (15–19 years) adolescence. Third, most included studies were cross-sectional (26 [70%] of 37), and all relied on retrospective self-report to identify exposures. Although some included studies reported a dose-dependent relationship between ACE exposure and poor health outcomes,1Anda RF Felitti VJ Bremner JD et al.The enduring effects of abuse and related adverse experiences in childhood: a convergence of evidence from neurobiology and epidemiology.Eur Arch Psychiatry Clin Neurosci. 2006; 256: 174-186Crossref PubMed Scopus (2635) Google Scholar, 2Felitti VJ Anda RF Nordenberg D et al.Relationship of childhood abuse and household dysfunction to many of the leading causes of death in adults.Am J Prevent Med. 1998; 14: 245-258Summary Full Text Full Text PDF PubMed Scopus (9643) Google Scholar heterogeneity in construction of the exposure variable precluded meta-analysis of this relationship. As such, the report3Hughes K Bellis MA Hardcastle KA et al.The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis.Lancet Public Health. 2017; 2: e356-e366Summary Full Text Full Text PDF Scopus (1762) Google Scholar provides only weak evidence for a causal association between ACE exposure and poor health outcomes. One regrettable feature of Hughes and colleagues'3Hughes K Bellis MA Hardcastle KA et al.The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis.Lancet Public Health. 2017; 2: e356-e366Summary Full Text Full Text PDF Scopus (1762) Google Scholar report is that studies of high-risk populations (eg, people who were homeless or incarcerated) were excluded, premised on the view that few would have had no ACEs. Vulnerable populations are all too often excluded from health research.11UyBico SJ Pavel S Gross CP Recruiting vulnerable populations into research: a systematic review of recruitment interventions.J Gen Intern Med. 2007; 22: 852-863Crossref PubMed Scopus (262) Google Scholar Given the disproportionate burden of ill health in such individuals and probable disproportionate economic benefit from upstream, targeted prevention of this health burden,12Caspi A Houts RM Belsky DW et al.Childhood forecasting of a small segment of the population with large economic burden.Nat Hum Behav. 2016; 1: 0005Crossref Scopus (171) Google Scholar whether or not evidence gleaned from unselected populations is applicable is important to know. Given the association between exposure to at least four ACEs and key risk factors for incarceration (eg, an OR of 10·22 [95% CI 7·62–13·71] for problematic drug use and 8·10 [5·87–11·18] for violence perpetration) and that most included studies treated household criminality as an ACE (27 [73%] of 37), one fruitful avenue for future research will be to explore how life-course and intergenerational transmission of health inequity intersect with intergenerational transmission of incarceration risk. In recognition of the links between health adversity and criminal justice system exposure,13Wildeman C, Wang EA. Mass incarceration, public health, and widening inequality in the USA. Lancet 389: 1464–74.Google Scholar Hughes and colleagues3Hughes K Bellis MA Hardcastle KA et al.The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis.Lancet Public Health. 2017; 2: e356-e366Summary Full Text Full Text PDF Scopus (1762) Google Scholar recommend incorporation of ACE-informed practices into criminal justice settings—a recommendation that aligns well with suggestions in the ACE literature for a trauma-informed response to young people showing behavioural problems,14Greeson JK Briggs EC Layne CM et al.Traumatic childhood experiences in the 21st century.J Interpers Violence. 2013; 29: 536-556Crossref PubMed Scopus (75) Google Scholar such as those in the youth justice system.15Abram KM Teplin LA Charles DR Longworth SL McClelland GM Dulcan MK Posttraumatic stress disorder and trauma in youth in juvenile detention.Arch Gen Psychiatry. 2004; 61: 403-410Crossref PubMed Scopus (498) Google Scholar The systematic review and meta-analysis by Hughes and colleagues3Hughes K Bellis MA Hardcastle KA et al.The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis.Lancet Public Health. 2017; 2: e356-e366Summary Full Text Full Text PDF Scopus (1762) Google Scholar persuasively shows an association between multiple ACE exposure and poor health outcomes in adulthood. A crucial focus of future research will be to identify factors associated with good health outcomes among those exposed to multiple ACEs—that is, studies of resilience. Evidence-based efforts to increase resilience in children and adolescents will disproportionately benefit disadvantaged communities in which ACE exposure is high, thus directly addressing the Sustainable Development Goal of reducing inequalities. We declare no competing interests. The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysisTo have multiple ACEs is a major risk factor for many health conditions. The outcomes most strongly associated with multiple ACEs represent ACE risks for the next generation (eg, violence, mental illness, and substance use). To sustain improvements in public health requires a shift in focus to include prevention of ACEs, resilience building, and ACE-informed service provision. The Sustainable Development Goals provide a global platform to reduce ACEs and their life-course effect on health. Full-Text PDF Open AccessAustralia's Stolen Generations: sorry is not enoughSorry. A simple word, yet a powerful word. A word that, when pronounced by the then Prime Minister of Australia, Kevin Rudd, in Parliament on Feb 13, 2008, moved the nation. This historic apology, to the estimated 100 000 Aboriginal and Torres Strait Islander people who were forcibly removed from their families as children, formally acknowledged the deep pain, suffering, and injustices caused by decades of discrimination. In his landmark speech, Kevin Rudd expressed a heartfelt apology to the Stolen Generations and their families, assuring all Australians that it was time to close the gap between Indigenous and non-Indigenous Australians. Full-Text PDF Open Access