tACS for Working Memory in Schizophrenia

Inclusion Criteria: * Aged 18-50 years, meeting the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria for schizophrenia, confirmed by the Structured Clinical Interview for DSM-5 (SCID-5). * Spatial span T-score \<40 on the MATRICS Consensus Cognitive Battery (MCCB). * Taking 1-2 antipsychotic medications, with stable dosage for at least 1 week prior to enrollment. No use of mood stabilizers, antidepressants, or excessive benzodiazepines (lorazepam equivalent \>2 mg/day). The type and dosage of antipsychotic medications remain unchanged during the treatment period. * Impaired functioning in daily activities. * Willing to participate in this study and provide written informed consent. Exclusion Criteria: * Previously diagnosed with or comorbid any other DSM-5 mental disorder besides schizophrenia. * Presence of significant mood symptoms or substance use disorder (other than caffeine and/or tobacco). * Presence of any contraindication to transcranial alternating current stimulation (tACS). * Received other forms of electrical or magnetic stimulation therapy within 1 month prior to enrollment. * History or current presence of any major physical illness, neurological disorder, or traumatic brain injury that may affect brain structure or function. * Pregnant or breastfeeding women, or women planning to become pregnant during the study period.