Early childhood stress and amygdala structure in children and adolescents with neurodevelopmental disorders

Children and adolescents with neurodevelopmental disorders such as autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) may be more susceptible to early life stress compared to their neurotypical peers. This increased susceptibility may be linked to regionally-specific changes in the striatum and amygdala, brain regions sensitive to stress and critical for shaping maladaptive behavioural responses. This study examined early life stress and its impact on striatal and amygdala development in 62 children and adolescents (35 males, mean age = 10.12 years, SD = 3.6) with ASD (n = 14), ADHD (n = 28), or typical development (TD, n = 20) across two cohorts. We assessed stress from various sources, including from the family environment, loss of loved ones, social stress, and illness/injury. We further examined parenting styles as potential moderators of the effects of early life stress. Volumes of the striatum and amygdala were extracted using an automatic segmentation algorithm. Significant group differences in childhood stress exposure were observed (F = 3.29, df = 8, p = 0.002), with autistic children facing more early life stressors (social stress, illness/injury) compared to those with ADHD and neurotypical peers (both, p < 0.002). In autistic children, amygdala volumes were significantly associated with early life stress related to the familial environment, experiences of significant loss, and illness/injury (all, p < 0.03). Positive parenting moderated these effects. These findings suggest that autistic children are more likely to experience early life stress and exhibit region-specific changes in the amygdala, a key brain region implicated in emotional processing and stress responses. This underscores the need for targeted interventions to support autistic children in managing early life stress to potentially mitigate its impact on brain development.