Intermittent Theta Burst Stimulation Over Left DLPFC May Have Clinical Utility

A systematic review and network meta-analysis from JAMA Network Open has found that intermittent theta burst stimulation (iTBS) over the left dorsolateral prefrontal cortex (DLPFC) is associated with improved outcomes among patients with schizophrenia.

Theta burst stimulation approaches may be a noninvasive approach for managing negative symptoms in schizophrenia, but conflicting outcomes about their clinical utility in schizophrenia have been reported.

To clarify the effect and best approaches for TBS in schizophrenia, researchers from Fujita Health University School of Medicine in Japan searched publication databases through May 2024 for relevant randomized controlled trials. The primary outcomes were the improvement in Scale for the Assessment of Negative Symptoms (SANS) and/or Positive and Negative Syndrome Scale (PANSS) scores. The researchers also considered depressive symptoms, anxiety symptoms, overall cognitive function, discontinuation rates (all-cause and adverse events), headache incidence, and dizziness occurrence.

The pooled study population comprised 1424 patients with schizophrenia or predominantly negative symptoms of whom 44.3% were men with a mean age of 40.5 years.

 The trials evaluated 9 TBS protocols of continuous TBS (cTBS) over the left primary motor cortex, over the left temporoparietal cortex, over the left and right temporoparietal cortex, or over the right inferior parietal lobule or iTBS over the cerebellar vermis (CV), over the left DLPFC, over the left inferior frontal gyrus, over the left supplementary motor area, or over the right DLPFC.

In the network meta-analysis, iTBS over the left DLPFC was associated with a greater reduction in negative symptom scores than sham treatment (standardized mean difference [SMD], -0.89; 95% CI, -1.24 to -0.55) or iTBS over the CV (SMD, -0.99; 95% CI, -1.76 to -0.22).

Similarly, compared with sham treatment, iTBS over the left DLPFC reduced overall symptom scores (SMD, -0.81; 95% CI, -1.15 to -0.48), depressive symptom scores (SMD, -0.70; 95% CI, -1.04 to -0.37), and anxiety symptom scores (SMD, -0.58; 95% CI, -0.92 to -0.24). The treatment was also associated with lower PANSS general subscale scores (SMD, -0.57; 95% CI, -0.89 to -0.25) and improved overall cognitive function scores (SMD, -0.52; 95% CI, -0.89 to -0.15).

In the pairwise meta-analysis, iTBS over the left DLPFC was associated with improved negative symptom scores compared with sham treatment (SMD, -0.94; 95% CI, -1.33 to -0.54). Larger effect sizes were observed in studies that included patients receiving higher antipsychotic doses, that used more pulses during treatment, and that used SANS as the primary outcome.

The study authors concluded, “iTBS over the [left] DLPFC was associated with improved scores for negative, depressive, anxiety, and cognitive symptoms in individuals with schizophrenia…These findings suggest that iTBS over the [left] DLPFC has the potential to become a novel treatment for individuals with schizophrenia.”

The limitations of this study included the small sample sizes and the pooling of data from patients receiving various antipsychotics at differing dosages.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

This article originally appeared on Psychiatry Advisor