A review of transcranial magnetic stimulation for treating negative symptoms of schizophrenia

Abstract

Introduction

The finding of prefrontal dysfunction in schizophrenia patients with negative symptoms (NS) has raised interest in using transcranial magnetic stimulation (TMS), which can modulate prefrontal function and dopamine release, as potential treatment for NS.

Objective

To briefly review current literature concerning the use of TMS as treatment for NS.

Aims

To assess whether current evidence supports the use of TMS for NS.

Methods

Narrative review of articles found through a PubMed database search using the keywords “transcranial magnetic stimulation”, “schizophrenia”, and “negative symptoms” between 1998 and 2015.

Results

Up to date, reviews of randomized sham-controlled studies found positive effects of TMS in NS. However, they exposed several methodological difficulties. More recent studies, reviewed in this poster, tried to overcome these, using results from multiple centers, larger samples and blinding. Various TMS techniques were studied, differing in frequency, motor threshold (MT), stimulus location, and treatment duration. Overall, TMS continues to show promising results in reducing NS; particularly rTMS 10 Hz, for at least 15 sessions on the left dorsolateral prefrontal cortex (DLPFC) at a 110% MT.

Conclusions

TMS may be a useful treatment for NS for patients not responding to pharmacological treatment alone. Studies remain difficult to compare due to different measures of outcome (PANSS and SANS being the most commonly used) and techniques. Furthermore, possible modulators of response include duration of illness, cognitive symptoms amelioration, medication and their dose, and different NS may respond differently to TMS. More studies are needed to better understand the utility of TMS in NS.

Disclosure of interest

The authors have not supplied their declaration of competing interest.