What It Means To Be Healthy: Adverse Childhood Events and Their Influence on Neuroanatomy and Behavior

Background: Adverse childhood experiences (ACE) have been studied extensively, particularly their relationship with neuroanatomy and mental illness. Specific regions of interest (ROI) related to emotional and stress response systems – such as the amygdala, hippocampus, nucleus accumbens, rostral anterior cingulate, and the medial prefrontal cortex (mPFC) – have been studied independently, regarding ACEs, but have rarely been considered together in one study. Independent lines of research have suggested that increased occurrences of ACEs lead to a greater risk of mental illness and decreased brain volumes in each of these specific ROI. This study aimed to combine all 5 ROI to determine how ACEs may relate to neuroanatomy. Sex differences have also been noted with respect to ACEs and thus perhaps one sex is in greater danger of developing mental illness based on their exposure to ACEs. Furthermore, previous research has suggested a relationship between increased reports of ACEs and increased anxiety in adulthood. The goal of this study is to establish potential relationships between ACEs, emotion and anxiety-related neuroanatomy, and anxious behavior in hopes of providing a tool to physicians who could utilize these relationships to predict who is at risk of mental illness. Methods: Twenty-Two clinically healthy subjects underwent anatomical magnetic resonance imaging (MRI) and self-reported their ACEs using the Childhood Trauma Questionnaire (CTQ). The CTQ enables us to quantify ACEs and compare them to ROI, anxiety, and compare scores between sex. Using the subject’s MRI, the software Freesurfer was used to identify and quantify separate brain regions and measure their relative volumes. The State-Trait Anxiety Inventory was used to quantify the trait anxiety of each individual. Results: No significant results were found between ACEs and neuroanatomy of the healthy subjects, nor were there any significant sex differences as suggested by prior research. However, statistical analysis did find a significant difference between ACEs and anxiety. Increased ACEs are associated with increased levels of anxiety in adulthood. Sexual trauma appears to drive this result. Conclusion: Although prior research suggested that increased prevalence of ACEs is associated with decreased volume of specific ROI and an increased risk of mental illness, no such findings were discovered in this study with healthy individuals. However, there does appear to be a relationship between the amount of trauma experienced and anxiety in healthy individuals. Healthy individuals with a higher prevalence of ACEs have higher trait anxiety in adulthood compared to those with fewer ACEs