Multi-target TMS for Schizophrenia Negative Symptoms

Schizophrenia is a chronic and severe mental disorder. Although antipsychotic medications are effective for positive symptoms, they offer limited improvement for negative symptoms and cognitive deficits. Effective treatments for these symptoms are still lacking. To address current clinical bottlenecks, there is an urgent need to develop novel, effective treatment strategies. Repetitive transcranial magnetic stimulation (rTMS) is a recently developed neuromodulation technique. The latest evidence-based guidelines indicate that the level of evidence for rTMS in treating schizophrenia remains low (i.e., Level C evidence, possibly effective). However, the critical parameter of target selection has not received sufficient attention. This randomized controlled trial (RCT) is the first to evaluate the efficacy and safety of a multi-target TMS protocol targeting the Right Orbitofrontal Cortex (R-OFC), Left Dorsolateral Prefrontal Cortex (L-DLPFC), and Left Inferior Parietal Lobe (L-IPL) for negative symptoms of schizophrenia. MRI-guided neuronavigation will be used to localize targets in each subject. The intensity of TMS stimulations is set to 80-120% of resting motor threshold (RMT). A total of 50 TMS sessions will be administered. The stimulation sequence will be R-OFC (1 Hz) → L-DLPFC (iTBS) → L-IPL (iTBS). The first target (R-OFC) will receive 720 pulses at 1 Hz, while the second and third targets (L-DLPFC and L-IPL) will each receive 900 pulses of iTBS. Five sessions will be delivered per day for 10 consecutive working days, with a 60-minute interval between sessions. Clinical assessments, cognitive evaluations, and resting-state functional Magnetic Resonance Imaging (MRI) scans will be performed before and after TMS treatment.