👤 Revathi Boyina

Affective disorders such as depression, anxiety disorders and suicidality are major contributors to global psychiatry. The "chemical imbalance" theory has been traditionally used; however recent research suggests that neurotransmitter dysfunction may represent an important early contributor within a broader, bidirectional cascade of cellular changes. Stress responses and neural circuits are disrupted by dysregulation of the serotonergic, noradrenergic, dopaminergic, GABAergic, and glutamatergic systems, which leads to oxidative stress, excitotoxicity, neuroinflammation, and decreased trophic support. Reduced brain-derived neurotrophic factor (BDNF) signaling, dendritic retraction, synapse loss, and apoptotic susceptibility are the common pathways that result in both amygdala hyperactivity and structural atrophy in the hippocampus and prefrontal cortex. Rumination, fear, anhedonia, cognitive impairment, and suicidal ideation are clinical manifestations of the ensuing circuit failure. This study proposes a unified model of pathogenesis in which increasing cellular damage is driven by neurotransmitter dysregulation, integrating evidence from both the neurochemical and cellular domains. Reassessing the delayed but plasticity-enhancing benefits of SSRIs and SNRIs, the quick synaptic repair brought about by NMDA antagonists like ketamine, and the potential of new drugs that target oxidative stress, inflammation, and glutamate receptor subtypes are some of the therapeutic implications. Lastly, it is highlighted that developing biomarkers for oxidative damage and neuroinflammation is an essential next step in the development of precision psychiatry. This paradigm aims to shift the emphasis from regulating neurotransmitters to promoting cellular resilience and rebuilding brain circuits in order to reimagine the future of treatment for depression, anxiety, and suicidality. Show less