Rapid-rate transcranial magnetic stimulation (rTMS) was administered to
10 healthy volunteers on different days over the right or left prefrontal
cortex, midfrontal cortex, occipital cortex, or cerebellum. Mood
(self-rated), reaction time, and hormone levels were serially measured.
Consistent with a previous study, comparison of hemispheres revealed
significant associations with decreased happiness after left prefrontal
rTMS and decreased sadness after right prefrontal rTMS. Stimulation of all
three prefrontal regions, but not the occipital or cerebellar regions, was
associated with increases in serum thyroid- stimulating hormone. There was
no effect on serum prolactin. rTMS applied to prefrontal cortex is safe and
well tolerated and produces regionally and laterally specific changes in
mood and neuroendocrine measures in healthy adults. rTMS is a promising
tool for investigating prefrontal cortex functions.