Repetitive transcranial magnetic stimulation for negative symptoms of schizophrenia: A randomized controlled pilot study☆☆☆
Received 6 February 2007; received in revised form 13 March 2007; accepted 17 March 2007. published online 10 May 2007.
Abstract
Background
Negative symptoms in schizophrenia are associated with deficits in executive function and frequently prove highly resistant to neuroleptic medication. Using repetitive transcranial magnetic stimulation (rTMS) to activate the prefrontal cortex has been suggested as a treatment for negative symptoms.
Methods
We performed a double-blind randomized controlled pilot study of real versus sham rTMS for negative symptoms in schizophrenia. 17 right-handed patients with prominent negative symptoms (PANSS negative subscore ≥20) were randomized to a 10 day course of real (n=8) or sham rTMS (n=9) applied to the left dorsolateral prefrontal cortex (20 trains per day, 10 s treatment at 10 Hz, 50 s inter-train interval, 110% of motor threshold). The primary outcome measure was PANSS negative symptom score. Secondary outcomes included mood, cognitive function and side-effects. Patients were followed-up two weeks afterwards. The main effect of treatment arm was evaluated across end of treatment and two-week follow-up time points using ANCOVA.
Results
All subjects completed the treatment course. There was no significant difference between the two groups on PANSS negative symptom scores at either time point. At the end of treatment, no subjects in either group met the criterion for response (i.e. a 20% reduction in baseline PANSS negative symptom score). The real rTMS group had better delayed recall on a test of verbal learning than the sham group at 2 week follow-up.
Conclusions
Real rTMS was not found to be better than sham rTMS in alleviating negative symptoms of schizophrenia although it was associated with some improvement in aspects of cognitive function at follow-up.
☆ Role of Funding Source: This study was supported by a 2003 Ritter independent Investigator Award from the National Alliance for research on Schizophrenia and Depression, the Guy's and St Thomas' Charitable Foundation (R01126), the NHS R&D National Coordinating Centre for Health Technology Assessment (NCCHTA) (98/11/04), and the Psychiatry Research Trust. These organisations had no further role in study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the paper for publication. The views and opinions expressed herein do not necessarily reflect those of any of these organisations.
☆☆ Contributors: DM McLoughlin designed the study and wrote the protocol. A Mogg performed the literature searches, undertook the statistical analyses and wrote the first draft of the manuscript. All authors contributed to and approved the final manuscript.
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