Efficacy of intensive bilateral temporoparietal continuous theta burst stimulation for auditory verbal hallucinations in schizophrenia: a randomized sham-controlled trial

Trans-cranial magnetic stimulation (TMS) can noninvasively modulate specific brain regions to dissipate auditory verbal hallucinations (AVH) in schizophrenia. Citing critical involvement of temporoparietal cortex (TPC) in AVH, we aimed to study the effect of continuous theta burst stimulation (cTBS) targeting bilateral TPC in schizophrenia subjects with AVH, on a randomized rater blinded placebo control trial. 59 patients were randomly allocated to active and sham groups. They received 20 cTBS sessions (2 per day: first right TPC, then left TPC) 5 days a week for 2 weeks. PANSS (Positive and Negative Syndrome Scale), AVHRS (Auditory vocal hallucination rating scale), PSYRAT-AH (Psychiatric symptoms rating scale- Auditory hallucinations scale), CDSS (Calgary depression scale for schizophrenia), SCoRS (Schizophrenia cognition rating scale), CGI-S (Clinical global impression-severity) were assessed at baseline, immediately post 20(th) session and 2 weeks post-TBS. 50 patients (25-active, 25-sham) completed the study. Conducting an intention to treat analysis, we found a significant group*time effect for PANSS, AVHRS, PSYRAT-AH, CDSS, SCoRS, CGI-S but when controlled for confounding variables, only PANSS-PS (F=26.617, p<0.001), PANSS-TOTAL (F=23.671, p<0.001), AVHRS (F=17.779, p<0.001), PSYRAT-AH (F=11.385, p<0.001) and CGI-S (F=28.462, p<0.001) retained significance. We conclude that cTBS over TPC is safe and has efficacy in AVH in schizophrenia.