In Search of HPA Axis Dysregulation in Child and Adolescent Depression

Dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis in adults with major depressive disorder is among the most consistent and robust biological findings in psychiatry. Given the importance of the adolescent transition to the development and recurrence of depressive phenomena over the lifespan, it is important to have an integrative perspective on research investigating the various components of HPA axis functioning among depressed young people. The present narrative review synthesizes evidence from the following five categories of studies conducted with children and adolescents: (1) those examining the HPA system’s response to the dexamethasone suppression test (DST); (2) those assessing basal HPA axis functioning; (3) those administering corticotropin-releasing hormone (CRH) challenge; (4) those incorporating psychological probes of the HPA axis; and (5) those examining HPA axis functioning in children of depressed mothers. Evidence is generally consistent with models of developmental psychopathology that hypothesize that atypical HPA axis functioning precedes the emergence of clinical levels of depression and that the HPA axis becomes increasingly dysregulated from child to adult manifestations of depression. Multidisciplinary approaches and longitudinal research designs that extend across development are needed to more clearly and usefully elucidate the role of the HPA axis in depression

Tracking the evolution of intergranular corrosion through twin-related domains in grain boundary networks

Steels: clustered coherent twins stop corrosion Clustered twin grain boundaries in stainless steel can stop intergranular corrosion, but only if they are coherent. A team led by Mitra Taheri at Drexel University in the USA analyzed microstructural regions in a 316 stainless steel where all grain boundaries were twinned and found that, when the twins in these clusters were coherent or had a low misorientation angle, they arrested interganular corrosion. They emphasized this effect by engineering more coherent and low-angle grain boundaries with thermomechanical processing, leading to larger twin-related domains. In contrast, twinned clusters with high-angle grain boundaries consistently failed at resisting corrosion, a similar manner to the rest of steel. Twin-related domains may therefore be a good predictor of intergranular corrosion and may help us mitigate metal damage