The cerebrospinal fluid (CSF) of animals exposed to electroconvulsive shock (ECS) has anticonvulsant properties when injected into naive animals. The present study investigated whether the CSF of humans exposed to 1 or 10 Hz repetitive transcranial magnetic stimulation (rTMS) has similar properties. Using a 4 day rat flurothyl kindling seizure model we found that the kindling rate was significantly decreased by intraventricular injection of CSF from depressed patients exposed to 1 Hz rTMS. The CSF from patients that underwent 10 Hz rTMS showed a trend toward an increased kindling rate. These results support the similarity of ECS and rTMS and suggest that 1 Hz and 10 Hz rTMS produce distinct physiologic changes.