Effects of repetitive transcranial magnetic stimulation on auditory hallucinations refractory to clozapine.

OBJECTIVE

To study the therapeutic effects on auditory hallucinations refractory to clozapine with 1-Hz repetitive transcranial magnetic stimulation (rTMS) applied on the left temporoparietal cortex.

METHOD: Eleven patients with schizophrenia (DSM-IV) experiencing auditory hallucinations (unresponsive to clozapine) were randomly assigned to receive either active of rTMS (N = 6) or sham stimulation (N = 5) (with concomitant use of clozapine) using a double-masked, sham-controlled, parallel design. A total of 160 minutes of rTMS (9600 pulses) was administered over 10 days at 90% motor threshold. The study was conducted from January 2003 to December 2005.

RESULTS

There was a reduction in hallucination scores in both groups, which persisted during follow-up in the active group for the items reality (p = .0493) and attentional salience (p = .0360). Both groups showed similar patterns of symptomatic changes on subscales (negative symptoms, general psychopathology) and total scores of the Positive and Negative Syndrome Scale, Clinical Global Impressions scale, and Visual Analog Scale.

CONCLUSION

Active rTMS in association with clozapine can be administered safely to treat auditory hallucinations, although its clinical utility is still questionable. No significant clinical effects were observed in the sample studied, possibly because it was too small and/or due to its high refractoriness.