Cognitive effects of 1- and 20-hertz repetitive transcranial magnetic stimulation in depression: preliminary report.
OBJECTIVE
To determine the cognitive effects of daily repetitive transcranial magnetic stimulation (rTMS) administered under the conditions of a treatment trial for major depression.


BACKGROUND
Although daily left dorsal prefrontal rTMS has improved mood in some patients with treatment-refractory depression, potential cognitive side effects of extended daily treatment have not been systematically studied.


METHODS
In a randomized double-blind treatment study, 10 subjects (mean age, 42 +/- 15 years) with an episode of major depression received either 2 weeks of low-frequency (1 Hz) or high-frequency (20 Hz) rTMS (800 pulses, 20 trains over 20 minutes, 80% of motor threshold, 5 days per week) to the left dorsolateral prefrontal cortex and then were crossed over to the other treatment condition. Patients received cognitive testing at baseline and after the first and second weeks of low- or high-frequency rTMS, which was examined by repeated-measures ANOVA.


RESULTS
Of 16 cognitive measures tested after 1 or 2 weeks of rTMS compared with baseline status, none showed deterioration, and the only significant main treatment effect indicated improvement on a list-recall test from pre- to post-rTMS after 1 week (p <0.05).


CONCLUSIONS
These preliminary data suggest no gross deleterious cognitive effects of 2 weeks of 1- or 20-Hz rTMS at 80% of motor threshold over the left prefrontal cortex. Further cognitive studies of the effects of rTMS at other parameters used in clinical trials for mood disorders remain to be undertaken.
Little
J T
JT
Biological Psychiatry Branch, National Institute of Mental Health, Bethesda, Maryland 20892-1272, USA.
Kimbrell
T A
TA
Wassermann
E M
EM
Grafman
J
J
Figueras
S
S
Dunn
R T
RT
Danielson
A
A
Repella
J
J
Huggins
T
T
George
M S
MS
Post
R M
RM
D000328:Adult; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology; D003866:Depressive Disorder / Q000523:psychology / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D017397:Prefrontal Cortex / Q000502:physiology; D050781:Transcranial Magnetic Stimulation / Q000009:adverse effects* / Q000627:therapeutic use*