Hypothalamic-Pituitary-Adrenal (HPA) Axis: Unveiling the Potential Mechanisms Involved in Stress-Induced Alzheimer's Disease and Depression

The hypothalamic-pituitary-adrenal (HPA) axis plays a pivotal role in the body's response to stress, orchestrating the release of glucocorticoids. In chronic scenarios, these glucocorticoids contribute to various neurological disorders, including Alzheimer's disease (AD) and depression. This abstract explores the potential mechanisms through which HPA axis dysregulation links stress-induced pathways to the pathogenesis of AD and subsequent depression. Chronic stress triggers prolonged HPA axis activation, resulting in elevated cortisol levels, which can lead to hippocampal atrophy, synaptic dysfunction, and neuroinflammation, recognized as key pathological features of AD. These alterations impair cognitive function and may exacerbate amyloid-beta plaque formation and tau hyperphosphorylation, hallmarks of AD. Concurrently, persistent cortisol elevation affects the prefrontal cortex and limbic structures, contributing to depressive symptoms. The interplay between chronic stress, HPA axis dysregulation, and neuroinflammation is crucial in understanding the comorbidity of AD and depression. Unveiling these mechanisms provides insights into potential therapeutic targets aimed at modulating the HPA axis and reducing stress-induced neurodegeneration, offering a dual benefit in managing both AD and depression. Further research is essential to elucidate the precise molecular pathways and develop effective interventions to mitigate the impact of chronic stress on brain health.