Transcranial direct current stimulation may be beneficial for refractory auditory hallucinations in schizophrenia.

Despite adequate pharmacological therapy, up to 30% of schizophrenia patients suffer from treatment-refractory auditory hallucinations (TRAH). Studies defining the role of transcranial direct current stimulation (tDCS) in the management of auditory hallucinations have shown mixed results.

To address the controversial efficacy of this treatment strategy, recently a meta-analysis was published in Asian Journal of Psychiatry by Jiang et al. The authors have shown that adjunctive tDCS is not more efficacious than sham tDCS in improving auditory hallucinations symptoms. But subgroup analysis suggested that twice-daily stimulation or ≥ 10 stimulation sessions may be beneficial in this regard.

Auditory hallucinations are a hallmark symptom of schizophrenia. These symptoms are often distressing, especially when verbal content is threatening, derogatory, or abusive in nature. Persistent auditory hallucinations have been associated with emotional distress, and may increase risk of suicide and acts of violence. Despite adequate pharmacological therapy, up to 30% of schizophrenia patients suffer from treatment-refractory auditory hallucinations (TRAH).

Eight double-blind RCTs covering 329 schizophrenia patients (168 in active tDCS group, 161 in sham tDCS group) were included to systematically examine the efficacy and tolerability of adjunctive tDCS for auditory hallucinations symptoms as measured by the AHRS in patients with schizophrenia experiencing TRAH.

Although no advantage of active tDCS on auditory hallucinations was found compared to sham, subgroup analyses revealed that active tDCS with twice-daily stimulation and active tDCS with ≥ 10 stimulation sessions, showed a significantly better therapeutic effect than sham in improving auditory hallucinations symptoms.

Apart from loudness and number of voices, no significant differences were found regarding the improvement of auditory hallucination symptoms as measured by the AHRS (i.e., frequency, length, reality, attentional salience, and level of distress). No significant differences were found with regard to total psychopathology as measured by PANSS.

In conclusion, this meta-analysis indicates that the effects of tDCS for auditory hallucinations symptoms were influenced by the tDCS parameters. Twice-daily stimulation or ≥ 10 stimulation sessions may be needed to improve auditory hallucinations symptoms in schizophrenia patients with TRAH.

Source: Asian Journal of Psychiatry: https://doi.org/10.1016/j.ajp.2022.103100