The process of ageing is characteristic of multicellular organisms associated with late stages of the lifecycle and is manifested through a plethora of phenotypes. Its underlying mechanisms are correlated with age-dependent diseases, especially neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD) and multiple sclerosis (MS) that are accompanied by social and financial difficulties for patients. Over time, people not only become more prone to neurodegeneration but they also lose the ability to trigger pivotal restorative mechanisms. In this review, we attempt to present the already known molecular and cellular hallmarks that characterize ageing in association with their impact on the central nervous system (CNS)’s structure and function intensifying possible preexisting pathogenetic conditions. A thorough and elucidative study of the underlying mechanisms of ageing will be able to contribute further to the development of new therapeutic interventions to effectively treat age-dependent manifestations of neurodegenerative diseases.

Plasticity is a fundamental property of the brain that enables the nervous system to respond appropriately to internal and external stimuli. It primarily involves changes at the synaptic level, mediated by a wide array of molecules, ultimately leading to cognitive and behavioral changes. This review critically contrasts the developmental timing and mechanisms of plasticity in Autism spectrum disorder (early hyperplasticity and excitation–inhibition imbalance) versus Schizophrenia (adolescent overpruning and NMDAR hypofunction) and evaluates evidence for interventions that harness plasticity to improve cognitive and behavioral outcomes. Preclinical and small clinical studies suggest that interventions targeting plasticity-related pathways may improve specific cognitive and behavioral domains. However, effects appear to be symptom-domain-specific and protocol-dependent and larger randomized controlled trials are needed to confirm efficacy. Cognitive remediation for Schizophrenia has been associated with improved executive function and increased hippocampal volume, while virtual reality-based training for Autism spectrum disorder has shown gains in attention and planning skills. By highlighting both molecular mechanisms and therapeutic strategies, this review aims to provide an integrated perspective on how plasticity-targeted interventions could be optimized across neurodevelopmental and neuropsychiatric disorders.