THE BIOLOGICAL AND NEUROLOGICAL CHANGES IN THE ADULT BRAIN DUE TO CHRONIC ANXIETY, STRESS, AND DEPRESSION

Abstract

Health conditions including long-term anxiety, stress, and depression have become
increasingly prevalent in today’s society. These conditions have been said to have reached epidemic levels while they also significantly impact a vast percentage of the adult population. Also referred to as mental health disorders, these conditions are often exacerbated by factors such as modern lifestyle demands and environmental stressors. Consequently, not only do they impact patients’ emotional well-being but they also induce substantial biological and neurological changes in the adult brain. In essence, prolonged exposure to stress is noted to activate the hypothalamic-pituitary-adrenal (HPA) axis, resulting in cortisol dysregulation. Thus, affecting critical brain regions such as the hippocampus, amygdala, and prefrontal cortex. As a result, these regions undergo structural modifications, including hippocampal atrophy, prefrontal cortex thinning, and amygdala hyperactivity. Ultimately, this contributes to cognitive deficits, emotional dysregulation as well as persistent symptoms of depression and anxiety. Recent studies have highlighted the roles of neuroinflammation, oxidative stress, and neurotransmitter imbalances in the pathophysiology of these disorders. According to studies, elevated levels of pro-inflammatory cytokines and reactive oxygen species interfere with neuroplasticity and synaptic functioning, while disruptions in serotonin, dopamine, and
norepinephrine systems further impair mood regulation. Additionally, epigenetic modifications and reduced expression of brain-derived neurotrophic factor (BDNF) have also been associated with long-term stress exposure, a revelation of a deeper molecular basis for the chronicity of these conditions. It is noteworthy that despite these adverse effects, the adult brain has the capacity to
3 retain a degree of plasticity that goes on to enable recovery through targeted interventions. These interventions include pharmacological treatments, psychotherapy, and lifestyle modifications. Additionally, some emerging therapies like transcranial magnetic stimulation (TMS) hold great promise for reversing and mitigating brain damage.