A controlled study of repetitive transcranial magnetic stimulation as a treatment of depression in the elderly

Rapid transcranial magnetic stimulation (rTMS) applied to the left dorsal l ateral frontal cortex has been shown to produce antidepressant effects. Old er depressed patients, however, in one study showed a lower response rate t han younger patients. The current study examined treatment response in 20 d epressed, treatment-refractory patients (mean age 60.7 +/-9.8 years) given five sessions of rTMS at 20 Hz for 2 seconds over 20 trains at 80% of motor threshold or identical placebo stimulation, after patients had been withdr awn from their antidepressants. There were no significant differences in Ha milton Depression Scale scores either before or after treatment at 7 days' follow-up. There were three responders to active treatment and three to sha m treatment and responders had significantly greater frontal lobe volume th an nonresponders; (p = .03). These findings suggest that the stimulation pa rameters used in this study were probably insufficient to produce treatment response and that frontal atrophy may interfere with the effectiveness of rTMS.