Effects of bilateral repetitive transcranial magnetic stimulation on prospective memory in patients with schizophrenia: A double‐blind randomized controlled clinical trial

Aims To investigate effects of repetitive transcranial magnetic stimulation (rTMS) on the prospective memory (PM) in patients with schizophrenia (SCZ). Methods Fifty of 71 patients completed this double‐blind placebo‐controlled randomized trial and compared with 18 healthy controls' (HCs) PM outcomes. Bilateral 20 Hz rTMS to the dorsolateral prefrontal cortex at 90% RMT administered 5 weekdays for 4 weeks for a total of 20 treatments. The Positive and Negative Symptom Scale (PANSS), the Scale for the Assessment of Negative Symptoms (SANS), and PM test were assessed before and after treatment. Results Both Event‐based PM (EBPM) and Time‐based PM (TBPM) scores at baseline were significantly lower in patients with SCZ than that in HCs. After rTMS treatments, the scores of EBPM in patients with SCZ was significantly improved and had no differences from that in HCs, while the scores of TBPM did not improved. The negative symptom scores on PANSS and the scores of almost all subscales and total scores of SANS were significantly improved in both groups. Conclusions Our findings indicated that bilateral high‐frequency rTMS treatment can alleviate EBPM but not TBPM in patients with SCZ, as well as improve the negative symptoms. Significance: Our results provide one therapeutic option for PM in patients with SCZ. This is the first study to investigate the effect of long‐term rTMS on PM impairment in patients with schizophrenia. We observed a positive result with active rTMS on EBPM, but not on TBPM, compared to sham stimulation. Our results provide one therapeutic option for PM in patients with SCZ.