Accelerated neurostimulation protocols for auditory hallucinations: a systematic review and meta-analysis

Area of Science:

• Neuroscience
• Psychiatry
• Medical Technology

Background:

• Auditory hallucinations (AH) are a core symptom of psychosis.
• Current treatments for AH have limitations, necessitating exploration of novel therapeutic approaches.
• Accelerated neurostimulation protocols offer potential for more efficient treatment delivery.

Purpose of the Study:

• To evaluate the efficacy of accelerated repetitive transcranial magnetic stimulation (rTMS) and transcranial Electrical Stimulation (tES) for treating auditory hallucinations (AH) and other psychotic symptoms.
• To compare the characteristics and effectiveness of accelerated neurostimulation protocols against standard approaches.
• To synthesize evidence from existing studies on accelerated rTMS and tES for psychotic symptoms.

Main Methods:

• A systematic literature search was conducted using PubMed with relevant MeSH terms and keywords.
• Eighteen studies (8 rTMS, 10 tES) were included in the meta-analysis.
• Standard mean difference (SMD) with 95% confidence intervals (CI) were calculated to assess treatment effects, with heterogeneity measured by Cochran's Q and I².

Main Results:

• Accelerated rTMS and tES demonstrated significant improvement in AH and positive psychotic symptoms (PPS) (SMD = 0.64, 95%CI = 0.77 to 0.51).
• fMRI guidance and continuous theta-burst stimulation (cTBS) showed superior effects.
• Sham-controlled studies indicated a moderate effect size for AH improvement (SMD = 0.34, 95%CI = -0.50 to 0.18), despite high heterogeneity. No significant improvement was observed for negative symptoms.

Conclusions:

• Accelerated neurostimulation protocols for AH appear to be as effective as non-accelerated methods, offering reduced treatment time and stimulus intensity.
• The findings suggest a therapeutic benefit for accelerated protocols in managing auditory hallucinations.
• Larger randomized controlled trials are necessary to validate these findings and inform clinical practice recommendations.