A randomized clinical trial of the therapeutic effect of Transcranial direct current stimulation on working Memory in recent-onset Schizophrenia

Significant cognitive impairments are common in patients with schizophrenia even in the initial recognizable episodes. Brain imaging in these patients also confirms the presence of a defect in the frontal cortex, which is closely related to impaired cognitive functions such as attention and memory (1, 2). Working memory, as a cognitive feature, is impaired in many neurological and psychological disorders such as Alzheimer disease, Parkinson disease, major depression, and schizophrenia (2, 3). Working memory is characterized as the ability to temporarily store and manipulate information in the brain, which leads to an increase in one's ability to think and perform complex functions (3). It is also essential for several key processes such as language comprehension, learning, and long-term memory (4). The neural circuitry involved in the working memory is located in the dorsolateral prefrontal cortex (DLPFC), which corresponds to the 9th and 46th Brodmann areas. According to the pathophysiology of schizophrenia, impaired memory function is consistent with defects in the DLPFC region (1).