Neuroplasticity in Major Depressive Disorder: A Systematic Review of Current Insights and Treatment Implications

Abstract

Major Depressive Disorder (MDD) is associated with impaired Neuroplasticity, which may be essential in understanding the neuroplastic mechanisms underlying MDD in order to improve diagnosis and treatment strategies. This review helps in the synthesis of evidence from recent studies exploring cortical excitability, biomarkers of treatment response, molecular modulation, and structural Neuroplasticity in depression. Findings show that individuals with MDD may exhibit altered cortical inhibition and facilitation compared to healthy controls, with evidence of impaired plasticity in the dorsolateral prefrontal cortex (DLPFC). Neuroplasticity-based measures, such as Transcranial Magnetic Stimulation TMS- evoked potentials, gamma power modulation, and Repetitive Transcranial Magnetic Stimulation rTMS-induced functional connectivity, show potential for treatment prediction. Pharmacological studies highlight serotonergic and noradrenergic modulation roles in enhancing plasticity, while ketamine-induced changes and magnetic seizure therapy provide insights into adaptations in Neuroplasticity. Structural studies reveal hippocampal and cortical thickness alterations, while behavioural interventions like exercise may promote neurocognitive benefits linking to Neuroplasticity. Collectively, the evidence underscores the multifaceted role of Neuroplasticity in MDD and the treatment implications.