Bilateral Versus Monolateral Repetitive Transcranial Stimulation in Depression

Repetitive transcranial magnetic stimulation (rTMS) has been recently FDA approved for the treatment of resistant depression. No accordance exists on which are the involved mechanisms of action and on which stimulation parameters, frequency and side are optimal.

To compare these different procedures we study patients with unipolar recurrent resistant major depressive disorder in a double-blind, controlled trial randomized to either sequential bilaterally on the right and left dorsolateral prefrontal cortex (DLPFC) or monolaterally on the right DLPFC. Patients will be randomized to receive sequentially low-frequency rTMS at 1 Hz to the right DLPFC and high-frequency rTMS at 10 Hz rTMS to the left DLPFC, or to receive low-frequency rTMS at 1 Hz to the right DLPFC. Significant antidepressant effect as expressed by a reduction of Hamilton Depression Scale score will be recorded in both the groups of patients.

Repetitive TMS will be administered using a MAGSTIM rapid magnetic stimulator (Magstim Company, Ltd., Whitland, U.K.) and a 70-mm figure-eight shaped coils. In monolateral treatment in right DLPFC, three 140-second trains will be applied at 1 Hz and at 110% of RMT. There is a 30 seconds intertrain interval (total of 420 stimuli per session). In sequential treatment, the stimulation will be applied in the first to the right and then to the left dorsolateral prefrontal cortex. In right DLPFC will be applied three 140-second trains at 1 Hz and at 110% of RMT. There will be a 30 seconds intertrain interval (total of 420 stimuli per session). In left DLPFC will be applied twenty 5-second trains were applied at 10 Hz and at 100% of RMT. There will be a 25-second intertrain interval (total of 1000 stimuli per session). Patients will be treated from Monday to Friday, for a total of 15 days.

Patients will be treated from Monday to Friday, for a total of 15 days in the same timeframe of the active group right sided low frequency stimulation

Inclusion Criteria: Diagnostic and Statistical Manual-IV criteria for Depressive Major Episode Hamilton Rating Scale for Depression -28 (Ham-D)score ≥ 18 Failure to respond to a minimum of two courses of antidepressant medications for at least 6 weeks Exclusion Criteria: Any comorbid axis I disorder (except simple and social phobia) Any other significant medical, particularly neurologic, illnesses (seizures, head trauma and brain lesions)

Pallanti S, Bernardi S, Di Rollo A, Antonini S, Quercioli L. Unilateral low frequency versus sequential bilateral repetitive transcranial magnetic stimulation: is simpler better for treatment of resistant depression? Neuroscience. 2010 May 5;167(2):323-8. doi: 10.1016/j.neuroscience.2010.01.063. Epub 2010 Feb 9.