Cerebellar theta burst stimulation for the treatment of negative symptoms of schizophrenia: A multicenter, double-blind, randomized controlled trial.

Given the importance of the cerebellum in the pathophysiology of schizophrenia, the cerebellar vermis has been proposed as a new rTMS stimulation site for negative symptoms. In this study, 64 patients from 7 psychiatric hospitals were randomized into the study (n=32) or control (n=32) group. Intermittent theta burst stimulation (iTBS) (or sham stimulation) to the cerebellar midline was administered 5 times/week for 2 weeks. Psychotic symptoms were assessed with the Positive and Negative Symptoms Scale (PANSS) at baseline, the end of treatment, and 2, 6, 12, and 24 weeks after the treatment. Regarding the negative symptoms, the interaction effect between group and time was statistically significant, with the scores in the study group significantly lower than those in the control group at the 4 follow-ups after treatment, and the group difference was maximal at 24 weeks of follow-up. The main effect of time was significant; however, the main effect of group did not show statistical significance. Our study revealed that cerebellar iTBS may improve negative symptoms in schizophrenia patients, and the effect was more pronounced at 24 weeks after the end of treatment, which provides preliminary empirical evidence for the maintenance of efficacy after stimulation of this new site.