Repetitive transcranial magnetic stimulation (rTMS) as an augmentation treatment for the negative symptoms of schizophrenia: A 4-week randomized placebo controlled study

BackgroundIn the absence of effective treatments for the negative symptom complex of schizophrenia, we explored the effect of 4 consecutive weeks of repetitive transcranial magnetic stimulation (rTMS) exposure (20 sessions) as an add-on treatment to atypical antipsychotics.MethodsThree groups of 17 schizophrenic subjects each were exposed to 20 treatments of either placebo, 1 Hz (100 pulses per day = 2000 total) or 10 Hz (1000 pulses per day = 20,000 total) rTMS at 110% motor threshold over the left dorsolateral prefrontal cortex, while being maintained on their atypical antipsychotic. Subjects were evaluated at baseline, weeks 2 and 4, and at 4-week follow-up after the last treatment.ResultsThe primary outcome measure (change in Scale for Assessment of Negative Symptoms score) showed a statistically significant drop at weeks 2, 4, and 8 for the high frequency (10 Hz) group, but not the 1 Hz or placebo groups. Secondary outcome measures of the Wisconsin Card Sorting Test and SF-36 did not demonstrate any significant change.ConclusionsrTMS may serve as a relatively noninvasive treatment of the negative and neurocognitive deficits associated with schizophrenia.