The impact of adverse childhood experiences (ACEs) on health and well-being in young adulthood: a longitudinal analysis of data from the birth to twenty plus (Bt20+) cohort

Abstract

ACEs have gained increasing prominence in the public health arena with evidence emerging that they are highly prevalent, interrelated and associated with a range of adverse health and social outcomes. ACEs as a set of exposures was first defined by the ACE Study, a collaboration between the Centres for Disease Control and Prevention (CDC) and the Kaiser Permanente’s Health Appraisal Centre, Department of Preventive Medicine in San Diego, California. Many adverse health outcomes have been strongly associated with ACE experience, though evidence is scarce in low-and-middle income countries due to unavailability of data. This study therefore set out to: (i) determine the prevalence of ACEs in a South African population and the childhood factors that may influence the experience of ACEs; (ii) investigate the presence and extent of interrelatedness and clustering of ACEs in the young adult population; (iii) determine the association between ACEs and psychological distress as an index of mental well-being; and finally (iv) explore the differences in the prevalence of psychological distress between a rural and urban population, and investigate the role of interpersonal violence, household stress and community danger in this relationship. Methods Data for this study came from a birth cohort in Soweto, Johannesburg in South Africa. The cohort has been followed up since 1990, in what is now the Birth to Twenty Plus Study (Bt20+). Adverse childhood experiences (ACEs) were measured retrospectively at 22 years of age using a modified ACE questionnaire. The prevalence of ACEs in the sample was determined, as well as childhood factors associated with experiencing ACEs. In the next step, the presence of underlying ACE typologies was investigated using latent class analysis. Thirdly the association between ACEs and psychological distress in the presence of contemporary stress was investigated using hierarchical regression methods. Finally, the experience of psychological distress in the urban Bt20+ cohort was compared to that of a rural population sampled from the MRC/Wits-Rural Public Health and Health Transitions Unit (Agincourt), a health and socio-demographic surveillance system based in Northeast South Africa, in the province of Mpumalanga. Only females were included in this last step of the study and data on violence and household stress were also included in the analyses. The impact of ACEs on psychological distress could not be assessed in the rural sample due to unavailability of data. xxiii Results Regarding the prevalence of experiencing at least one ACE in the Bt20+ cohort, 88% reported at least one ACE. Over one third of respondents reported experiencing four or more ACEs and 15% experienced 6 or more ACEs. Of the childhood factors investigated, higher household socio economic status (SES) at 16 years of age and maternal marital status reduced the odds of ever experiencing ACEs as well as experiencing multiple ACEs. A high degree of co-occurrence was detected with many ACE exposures increasing the risk of experiencing others. Four distinct latent clusters of ACEs were identified: class one the “Low ACE” class, class two “Low abuse and neglect, medium household dysfunction”, class three “High emotional abuse and neglect, low household dysfunction” and class four “High emotional abuse and neglect, high household dysfunction”. Once again household socio-economic status at 16 years of age was an important factor influencing class membership. The proportion of participants in the Bt20+ cohort with psychological distress (PD) was 28%. Approximately 50% of those who had PD reported experiencing at least four ACEs, compared to 30% of those who had no PD, and 25% reported six or more ACEs, compared to 11% of those who did not have PD. Compared to those who experienced low levels of ACEs, participants who reported high ACE levels had nearly twelve times greater odds of experiencing high levels of adult stress. Interaction analyses showed that high levels of adult life stress increase the likelihood of PD by over 20 times compared to no stress, in the absence of ACEs. However, both low and high levels of ACEs had a significantly different effect in individuals with high adult stress compared to those with no adult stress. In the comparison analyses, the urban sample had higher levels of PD, interpersonal violence (IPV), household stress and community danger compared to the rural young women. A direct association between IPV and PD was observed in the urban young women independent of household stress, SES, community danger and demographic factors. Rural residents showed much greater sensitivity to the effect of household stress compared to the urban residents. Conclusions ACEs are highly prevalent and interrelated in this cohort of young adults. SES is an important factor in the experience of ACEs. The association between ACEs and PD is strong and the effect of ACEs needs to be considered in assessing mental well-being. The study of ACEs needs to account for the fact that they seldom occur alone. The interplay between ACEs and mental health xxiv and contemporary stress means the management of psychological distress needs to extend beyond current events and stressors. Further research is needed to assess if there is a difference in ACE experience in rural and urban environments and if this differentially impacts mental well-being.