Cognitive Deficits in Schizophrenia: Brain Deorganization and Neurorehabilitation

Schizophrenia is a complex psychiatric disorder that significantly affects individuals and society. Its etiology and pathophysiology remain unclear, in part due to its heterogeneity. Although the neurobiological background is not fully understood, schizophrenia is considered a polygenic disorder influenced by multiple genes. Current hypotheses, such as the N-methyl-D-aspartate (NMDA) hypothesis, and the role of glial cells are under investigation. The disease manifests through positive, negative, and cognitive symptoms, having an impact on emotion, perception, and behavior. In particular, cognitive decline affects two domains: neurocognition (verbal memory, fluency, processing speed, working memory, visual learning, attention, reasoning, and problem-solving) and social cognition. Although pharmaceutical treatments aim to alleviate clinical symptoms, recent studies indicate that neurorehabilitation and cognitive training can improve cognitive and clinical outcomes by modifying the neurobiological framework. Cognitive therapies, like cognitive remediation therapy, RehaCom, and cognitive behavioral training, are becoming prominent. Neuroimaging studies suggest that these therapies can reorganize brain structure, thereby enhancing cognitive functions and improving daily and social life.