Overview

Around 40% of schizophrenia patients present depressive symptoms, which are associated with elevated suicide and violence risk and poor prognosis and quality of life. Recent meta-analysis showed the effect size of antidepressants for depressive symptoms of schizophrenia patients was as low as 0.25, so new therapeutic approach is warranted.

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive, anesthesia-free brain stimulation therapy for treatment refractory depression. Currently, rTMS is classified as high-frequency stimulation (>5Hz, usually 10Hz or 20Hz) and low-frequency inhibition (usually 1Hz). Intermittent theta burst stimulation (iTBS) is a new variant of rTMS, with stimulation frequency as high as 50Hz. Compared with high-frequency rTMS, iTBS has similar therapeutic effect and shorter stimulation duration. Up to now, studies exploring treatment effect of rTMS or iTBS for schizophrenia patients mainly focused on negative symptoms rather than depressive symptoms. Therefore, this study aims to explore treatment effect of rTMS or iTBS of depressive symptoms, negative symptoms, cognitive function and physiological indices for schizophrenia patients.

Eligibility

Inclusion Criteria:

• Age ≥ 20 years
• Able to give informed consent
• Diagnosed with schizophrenia or schizoaffective disorder according to DSM-5
• Has a score ≥ 7 on Calgary depression scale for schizophrenia
• The principal psychotropic agents are not changed within one month of the first session of rTMS

Exclusion Criteria:

• DSM-5 defined substance use disorder (excluding tobacco) in the past 3 months
• Have clinically relevant cognitive impairment (e.g., delirium, intellectual disability or MMSE < 15)
• With electronic and/or magnetic implants (e.g. pacemaker, implantable cardioverter defibrillator [ICD], cerebral shunts, cochlear implant, etc.)
• With metallic or mechanic fragments (e.g., screws, plates, stents, clips, etc.)
• Pregnant, or has a pregnancy plan within 3 months
• With any known or history of neurological conditions including cerebral vascular accidents, epilepsy (or epileptiform waves detected by EEG prior to the first session of rTMS), brain tumor or space occupying lesion
• Received rTMS or iTBS treatment within 3 months
• Has a clinically significant abnormality on the screening examination that might affect safety, study participation, or confound interpretation of study results