Echoes of childhood trauma: the relationship between adverse childhood experiences, brain structure, and mental health in aging adults.

Bayesian statistical analysis provided strong evidence for an association between ACEs and both depression and anxiety symptoms in mid- to late adulthood.

• Cross-sectional data from the Hamburg City Health Study were used, with participants aged 46-78 years
• Total sample was 2,624 participants with available MRI data; the analysis sample was n = 1,900
• Mental health was quantified using the Patient Health Questionnaire-9 (PHQ-9) and the General Anxiety Disorder-7 (GAD-7) questionnaire
• ACEs were assessed using the 10-item ACE-questionnaire

The hypothesized mediation of the ACE-mental health relationship by hippocampus, amygdala, and dorsolateral prefrontal cortex morphology was not confirmed.

• Predefined regions of interest (ROI) were the hippocampus, amygdala, and dorsolateral prefrontal cortex
• Bayesian statistical analysis did not confirm the hypothesized mediation by ROI-level brain morphology
• This was a preregistered study with a priori defined ROIs and mediation hypotheses

Exploratory whole-brain voxel-based morphometry revealed significant regional grey matter volume reductions in individuals with 3 or more ACEs, affecting bilateral limbic and frontal regions.

• Regions affected in the 3 or more ACEs group included the nucleus accumbens, gyrus rectus, and insula
• Reductions were bilateral and confined to limbic and frontal regions at this threshold
• No increases in regional grey matter volume were observed for any ACE group

Individuals with 4 or more ACEs showed more pronounced and widespread grey matter volume reductions extending to additional brain regions.

• Additional regions affected in the 4 or more ACEs group included areas in the dorsolateral and medial prefrontal cortex, anterior cingulate cortex, inferior parietal and temporal gyri, occipital cortex, and cerebellum
• Reductions were described as 'more pronounced and widespread' compared to the 3 or more ACEs group
• No increases in regional grey matter volume were observed in this group either
• This pattern suggests a dose-dependent effect, with 4 or more ACEs marking 'a potential threshold for more distributed neuroanatomical alterations'

The findings suggest a dose-dependent relationship between ACE count and the extent of neuroanatomical alterations persisting into mid and late adulthood.

• The pattern of increasingly widespread grey matter reductions from the 3+ to 4+ ACE groups supports a dose-dependent effect
• Structural brain changes associated with ACEs were observed in a general population sample aged 46-78 years, extending evidence into aging populations
• The authors conclude these results 'extend the understanding of the possible effects of ACEs by providing evidence that structural changes associated with ACEs could last into mid and late adulthood similarly to mental health outcomes'