Lack of impact of repetitive High Frequency Transcranial Magnetic Stimulation on mood in healthy female subjects

Background: High Frequency repetitive Transcranial Magnetic Stimulation (HF-rTMS) is currently used as an experimental tool to induce mood changes in normal volunteers and as a treatment option for depression. However, HF-rTMS, mostly performed on the left dorsolateral prefrontal cortex (DLPFC), has yielded divergent results and effects on mood which seem to be oppositely lateralized between these two groups. The inconsistent results that have been reported might be explained by methodological heterogeneity and drawbacks. Methods: In this sham-controlled, single blind, crossover study, we tried to reproduce previous HF-rTMS findings of a negative mood induction in 28 healthy female subjects. To exclude individual anatomical differences, the left DLPFC was localised under magnetic resonance guidance (MRI). Mood assessment was performed before and just after HF-rTMS with Visual Analogue Scales and the Profile of Mood States. To detect possible delayed mood changes, ratings were also performed 30 min post HF-rTMS. Results: We were unable to demonstrate significant mood changes from baseline after one single active HF-rTMS session on the left DLPFC. Conclusions: Although this study controlled for several methodological problems, the hypothesis that one single session of HF-rTMS on the left DLPFC has negative mood effects in healthy female volunteers was not supported. (c) 2005 Elsevier B.V. All rights reserved.