Effects of 10 Hz repetitive transcranial magnetic stimulation (rTMS) on clinical global impression in chronic schizophrenia

We conducted a randomized, sham-controlled repetitive transcranial magnetic stimulation (rTMS) study in chronic schizophrenia in-patients (n = 35) to evaluate the therapeutic efficacy of 10 Hz stimulation. Patients, who were on stable antipsychotic treatment, were randomly assigned to the active or sham condition. In the active rTMS group, ten sessions with a total of 10,000 stimuli were applied over the left dorsolateral prefrontal cortex at 110% of motor threshold. The sham group received corresponding sham stimulation. Clinical improvement was measured by the Clinical Global Impression scale (primary outcome measure), the Global Assessment of Functioning Scale (GAF) and the Positive and Negative Symptom Scale (PANSS; secondary outcome measures). Between-group comparisons revealed no significant differences in clinical outcome variables. Only a subgroup of patients with pronounced negative symptoms developed some clinical improvement as indicated by significant changes in the GAF-scale. Besides there is some evidence for a more favourable clinical outcome within this subgroup after rTMS in the CGI-S and PANSS negative scale, too. In line with earlier investigations, our results suggest a moderate potentially clinically relevant treatment effect of prefrontal 10 Hz rTMS stimulation in chronic patients. However, in our study this beneficial effect was restricted to subjects with pronounced negative symptoms.