In this study, we assessed the therapeutic effects and safety of left dorsolateral prefrontal cortex (DLPFC) high-frequency repetitive transcranial magnetic stimulation (rTMS) on negative symptoms of schizophrenia. We evaluated the efficacy of rTMS on cognition in patients with chronic schizophrenia.

This is a randomized, sham-controlled, double-blinded trial. 47 patients diagnosed with schizophrenia on stable antipsychotic treatment were randomly assigned to active rTMS treatment group (n=25) or a sham rTMS treatment group (n=22). 25 patients in the active rTMS group received 10 Hz 110% rTMS, while 22 patients were subjected to sham rTMS, both being given 4-week treatment (5 days per week). Efficacy of negative symptom was assessed with the Scale for the Assessment of Negative Symptoms (SANS), the Positive and Negative symptom scale (PANSS) at baseline, the end of 4 weeks and 8 weeks. The cognitive function was assessed with CANTAB at baseline, the end of 4 weeks and 8 weeks .The side effects were assessed with Treatment Emergent Symptoms Scale at baseline and the end of 4 weeks.

Inclusion Criteria:

1. Right-handed;
2. meeting the diagnosis of schizophrenia for at least 2 years;
3. had been on anti-psychotic medications for more than 12 weeks;
4. with unresolved negative symptoms (SANS>20).

Exclusion Criteria:

1. with substance use disorders ;
2. with cerebral pathologies (e.g. seizure, aneurysm, stroke), intra-cranial metals, pacemakers, severe cardiovascular diseases;
3. receiving electroconvulsive therapy in the past 3 months.

This was a single-institution, randomized controlled, double blinded trial. Participants were randomized to receive, over 4 weeks, 20 sessions of either active or sham rTMS. Clinical assessment was performed at baseline, 4 weeks and 8 weeks by 2 psychiatrists blinded to the treatment assigned. Inter-rater reliability was satisfactory (κa=0.86).