Low socioeconomic status (SES) is associated with greater risk for symptoms of attention-deficit/hyperactivity disorder (ADHD). One mechanism through which SES may confer risk for ADHD is by influencing brain structure. Alterations to cortical thickness, surface area and subcortical volume have been associated with low SES and with the presence of ADHD across multiple studies. The current study examined whether cortical thickness, surface area or subcortical volume mediate the associations between SES and ADHD in youth 3–21 years old (N = 874) from the Pediatric Imaging, Neurocognition and Genetics Study. Freesurfer was used to estimate cortical thickness, surface area and subcortical volume from structural magnetic resonance imaging. Parents reported on demographics, family SES, ADHD diagnoses and the presence of child attention problems. Statistical mediation was assessed using a bootstrap resampling procedure. Controlling for parental ADHD, child age, gender, birth weight and scanner, children in low SES families were more likely to be in the ADHD group. Consistent with previous reports in this sample, low SES was associated with reduced surface area across the frontal lobe and reduced subcortical volume in the amygdala, cerebellum, hippocampus and basal ganglia. Of these regions, a significant indirect effect of SES on ADHD status through subcortical volume was observed for the left cerebellum (95% confidence interval: 0.004, 0.022), the right cerebellum (95% confidence interval: 0.006, 0.025), and the right caudate (95% confidence interval: 0.002, 0.022). Environmentally mediated changes in the cerebellum and the caudate may be neurodevelopmental mechanisms explaining elevated risk of ADHD in children in low SES families.
Decades of research have unequivocally shown that life stress is a central factor in the onset and course of almost every psychiatric disorder. However, the processes by which stress influences mental health are complex, and the integration of the myriad of biological and psychological systems involved requires a multidisciplinary perspective. Fortunately, scientists working from diverse vantage points have made huge advances in unpacking the complexities of stress-disorder relations. The Oxford Handbook of Stress and Mental Health provides a comprehensive, up-to-date overview of the science of stress and mental health. Topics covered include assessment issues, the role of stress in various mental disorders, developmental influences and individual difference factors that predict reactivity to stress, and treatment of stress-related mental health problems. Internationally recognized scholars in the field of stress and stress-related disorders have contributed their diverse expertise, providing both depth and breadth in terms of understanding stress and mental health. Chapters 1 to 4 provide a critical discussion of assessment issues in the domains of stress exposure and stress response. Chapters 5 to 14 review the relation of stress exposures to a broad range of mental health outcomes across the lifespan. Chapters 15 to 25 are concerned with understanding how the stress response unfolds at both psychological and neurobiological levels. Lastly, Chapters 26 to 33 addresses stress adaptation and resilience, as well as evidence-based treatments for stress and stress-related disorder. This volume will constitute an invaluable resource for students, established scientists, and clinicians looking for a comprehensive treatment of the topic of stress and mental health.