The purpose of this study was to examine the impact of ACEs on perceived stress, anxiety symptoms, and cortisol in a sample of mothers residing in rural Pakistan. Our results revealed that ACEs are associated with increased perceived stress and anxiety later in adult life. These findings contribute to previous work indicating that the number of ACEs an individual experiences predicts their psychological functioning in adulthood (10, 11, 37). When examining perceived stress, we found that most ACE indicators, including the continuous measure of ACEs, the dichotomous indicators for number of ACEs, and specific ACEs domains, predicted the outcome in a similar way, with the exception of neglect. Similarly, for anxiety symptoms, there was a significant association of the total ACE score, but not the individual indicators of number of ACEs or ACEs domains. Together, these results suggest that the cumulative effect of multidimensional early adversity, as captured by a continuous ACE measure, may be more important in predicting adult stress than the individual domains of adversity or individual indicators of ACEs.
In this sample, ACEs were consistently and strongly associated with perceived stress, and somewhat more weakly associated with the continuous version of the anxiety symptom scale, and weakly associated when dichotomized at clinically significant levels. The PSS captures one’s appraisal of situations as overwhelming or stressful, beyond the actual content of situations (38, 39). Our findings suggests that those who have ACEs are more likely to feel overwhelmed with any current conflict or instability (4, 40). Furthermore, accumulaton of disadvantges (i.e., a higher number of ACEs) increases the likelihood that individuals who had ACEs end up in a stressful environment later in life, potentially explaining the predictive power of ACEs on perceived stress (41).
Complementing the perceived stress measure, the assessment of generalized anxiety symptoms with the GAD-7 captures the experience of chronic worry and physiological dysregulation (e.g., muscle tension, restlessness) that are not explicitly tied to current stressors present in the environment. The focus is more on specific symptoms and less on the appraisal and subjective aspects of those symptoms, which is central to perceived stress (28, 31). Our findings with anxiety symptoms were not as consistent as with perceived stress, as can be seen in the finding that ACEs are associated with the continuous anxiety symptom count but not with anxiety at the dichotomized clinically meaningful level. This is consistent with the idea that ACEs might more strongly impact how adults appraise potentially stressful experiences as opposed to their body’s physiological responses to those experiences (42). This could also be due to differences in measurement between a continuous score and a dichotomous cut-off.
Somewhat surprisingly, we also found that those who reported experiencing neglect as children were less likely to report significant anxiety symptoms. This is contrary to previous literature suggesting that neglect is associated with heightened anxiety symptoms, though neglect also behaved strangely with perceived stress (ie: neglect was negatively associated with perceived stress) (43, 44). This result may be traced to mothers who have experienced neglect being less likely to report anxiety symptoms independent of their actual experience of anxiety due to desensitization to deprivation-related experiences that tend to be more frequent, yet individually less severe than threat-related ones (40, 45, 46). While disentangeling this finding is beyond the scope of this paper, desensitization and normalization mechanisms should be further explored. In Southeast Asian and sub-Saharan African studies, early adversity in the form of neglect was linked to emotional difficulties later in life (47). Additionally, neglect was not significantly associated with the continuous GAD-7 score, pointing to different relationships between neglect and clinically significant anxiety versus the continuous GAD-7.
When examining the association between ACEs and hair cortisol, we found that endorsing two ACEs or experiencing home violence were significant predictors of increased hair cortisol. This partially aligned with our hypothesis that early adversity is associated with increased HPA axis hyperactivity, and subsequent increase in cortisol production (14, 48). Interestingly, a study in India analyzed hair cortisol in children and found it to be linked with adversity (49). Other studies have shown that among early life experiences, violence particularly has a potent impact on programming the HPA axis (50). This is preliminary evidence that ACEs have downstream effects of adulthood HPA axis functioning. Future studies would benefit from a larger sample size to more fully investigate the relationship between ACEs exposure and cortisol.
In LMIC, home violence in the form of interpersonal violence is particularly common, which is also reflected in our sample (51, 52). Home violence was the only domain that significantly predicted cortisol, possibly because it is linked to consequences that are emotional in nature: isolation, fear, guilt, low self-esteem (53). Violence experienced at home may be internalized to a greater extent because it is physical, occuring closer to the child with a large presence in the child’s life. Domestic violence also increases the risk for other kinds of abuse (54). Young girls living in households with domestic violence are are at risk for developing internalizing mental health issues (55). Importantly, we did not control for current interpersonal violence, which might interact with earlier adverse exposures and mediate HPA axis activity. We also did not find associations between the emotion abuse items and cortisol. Threatening, violent behaviors lead to the activated kinds of outcomes we focused on compared to ones that stem from neglectful experiences, which tend to be emotional in nature (56).
This study benefited from a number of strengths. In particular, we investigated the impact of ACEs in many ways: as individual items, categorically, continuously, binary (any/none), and domains (neglect, home violence, family psychological distress, community violence). In particular, few prior studies have examined childhood adversity in the form of neglect (45). Neglect is the most common type of maltreatment, increasing the importance to explore it in research (40, 45). Thus, we broke neglect into its subtypes of emotional and physical. Neglect behaved differently from the other domains, and future studies should examine neglect separately in addition to investigating its impact alongside other types of ACEs. In addition to modeling ACEs in multiple ways, we also studied the outcomes from two angles--perceived stress and anxiety—to discern nuances between the two seemingly similar measures. Although PSS and GAD-7 appear to measure similar things, the results of our study point to their distinctive relationships with ACEs. Additionally, the inclusion of the cortisol subanalysis is another way to approach stress and anxiety, with cortisol representing a biological constrast to behavioral constructs, PSS and GAD-7. Finally, our study was situated in a LMIC context, where ACEs have been understudied yet pose a significant public health burden (57).
These results should be interpreted in the context of several limitations. First, the cortisol exploraratory analysis only included 90 women, potentially reducing the validity of the associations among ACEs and cortisol. Additionally, Another limitation is that the ACEs questionnaire involved recall bias due to questions asking about events that occurred years, if not decades ago. However, the ACEs questionare was designed to be asked retrospectively (World Health Organization, 2018). All of the measures were self-reported and focused on the appraisal of experiences rather than the actual objective content, providing another pathway to produce subjective results (42). ACEs have been found to be comorbid with low-income and low-education populations, which predispose people to stressful living environments. We attempted to address this by controlling for maternal education as an indicator of childhood socioeconomic status. However, we did not include current stressful life events and violence exposure.
These results inform our understanding of how ACEs are associated with perceived stress, anxiety, and HPA-axis functioning. ACEs were associated with heightened levels across all three domains of perceived stress, anxiety, and cortisol, with varying precision and strength of estimates. Our study attempts to disentangle adversity into subtypes (neglect, home violence, family psychological distress, community violence) to pinpoint the impact of specific adverse events on HPA axis functioning, and therefore mental health conditions related to stress. Most studies of ACEs have focused on higher-income, well-educated populations, yet toxic stress tends to be embedded in social disadvantage and intergenetational adversity is often comorbid with other forms of maltreatment (7). Future research should center on identifying potential moderators and mediators between ACEs and perceived stress and anxiety in order to create targeted interventions that support mental health among women who have experienced ACEs and reside in LMICs. For instance, social support, emotion regulation skills, and positive self-perceptions are powerful protective factors that buffer women from the harmful effects of ACEs. Interventions targeting girls within community or school setting that harness these protective factors or prevent the consequences of ACEs have the potential to lessen HPA axis hyperactivity, prevent the intergenerational transmission of adversity, and improve mental health outcomes in this population.