Treating auditory hallucinations with transcranial direct current stimulation in a double-blind, randomized trial

Area of Science:

• Neuroscience
• Psychiatry
• Neuromodulation

Background:

• Auditory hallucinations (AH) are a challenging symptom in medication-resistant psychiatric conditions.
• Transcranial direct current stimulation (tDCS) has been explored as a potential non-invasive neuromodulation treatment for AH.
• Previous studies on tDCS for AH have yielded inconclusive results, lacking large-scale trials.

Purpose of the Study:

• To investigate the efficacy of tDCS as a treatment for medication-resistant auditory hallucinations in a double-blind, placebo-controlled study.
• To assess the impact of tDCS on AH severity and other clinical and cognitive measures.

Main Methods:

• A double-blind, placebo-controlled trial involving 54 patients with medication-resistant AH.
• Patients received 10 sessions of either 2mA tDCS or placebo over five consecutive days.
• Anodal stimulation targeted the left dorsolateral prefrontal cortex, and cathodal stimulation targeted the left temporoparietal junction.

Main Results:

• A significant decrease in AH frequency and severity was observed over time in both tDCS and placebo groups.
• Scores on the Positive and Negative Syndrome Scale (PANSS) also improved significantly over time.
• No significant interaction effect between the treatment group and outcome measures was found, indicating no superior effect of tDCS over placebo.

Conclusions:

• The study found no evidence that tDCS is more effective than placebo for treating medication-resistant AH.
• Symptom improvement occurred in both groups, suggesting potential non-specific effects or spontaneous remission.
• Future research could explore tDCS in earlier stages of illness or investigate its capacity for inducing long-lasting neurophysiological changes.