Some Parameters of cTBS Reduce Auditory Hallucinations in Schizophrenia

Adjuvant continuous theta burst stimulation (cTBS) for more than 10 stimulation sessions and more than 6000 total pulses significantly improved auditory hallucinations among patients with schizophrenia, according to systematic review and meta-analysis study findings published in Frontiers in Psychiatry.

Although cTBS has been used as an adjuvant treatment for auditory hallucinations in schizophrenia, studies that explore the effectiveness of cTBS for improving hallucination burden have produced mixed results.

Therefore, investigators conducted a systematic review and meta-analysis to elucidate the efficacy and safety of cTBS for auditory hallucinations. The investigators searched 4 international databases from inception to mid-January 2024 for randomized controlled trials (RCTs), published in English, that evaluated adjuvant cTBS for the treatment of auditory hallucinations in schizophrenia or schizoaffective disorder. Participants who were included failed to respond sufficiently to at least 1 antipsychotic medication at the highest acceptable dosage, administered for at least 6 weeks.

The investigators included 4 RCTs in the analysis, for a pooled sample size of 151 participants (mean [SD] age, 37.78 [13.51] years) with auditory hallucinations. All studies had a low risk, according to the Cochrane risk of bias tool. Across studies, cTBS treatment duration ranged from 1 to 3 weeks and treatment sessions ranged from 10 to 80 minutes.

In the preliminary analysis, the investigators observed no significant advantage of cTBS over sham stimulation in reducing auditory hallucinations (standardized mean difference [SMD], -0.45; 95% CI, -1.01 to 0.12; P =.13; I²=61%).

However, in subgroup analyses that evaluated stimulation parameters, the investigators found that cTBS treatment that consisted of 10 or more stimulation sessions and 6000 or greater total pulses was associated with a statistically significant improvement in hallucination symptoms analysis (3 RCTs, n=87; SMD, -4.43; 95% CI, -8.22 to -0.63; P =.02; I²=47%), relative to sham stimulation. Further, the cTBS and sham groups exhibited no significant differences in their rates of discontinuation and adverse events.

“Although preliminary analysis did not reveal a significant advantage of adjuvant cTBS over sham stimulation, subgroup analysis showed that specific parameters of cTBS appear to be effective in the treatment of auditory hallucinations in schizophrenia,” the investigators concluded. Study authors wrote, “Given the important impact of different parameters such as stimulation session and number of pulses on the efficacy of cTBS, multicenter RCTs with a larger sample size are needed to determine an appropriate and standard cTBS protocol for the treatment of auditory hallucinations in the future.”

Systematic review and meta-analysis limitations include the underpowered sample sizes in all 4 RCTs, the concomitant use of antipsychotics was neither consistently reported nor standardized, and selection bias limited the search to studies published only in English.

This article originally appeared on Psychiatry Advisor