Can repetitive transcranial magnetic stimulation prolong the antidepressant effects of sleep deprivation?

Repetitive transcranial magnetic stimulation (rTMS) has been proposed for stabilizing the antidepressant effect of sleep deprivation (SD) by preventing the relapse after a night of recovery sleep. In this study, we aimed to replicate these data coming from a small pilot study in a larger patient sample.

Thirty-seven patients were randomly assigned to receive either active or sham rTMS on four consecutive days after one night of SD. The majority of the participants had experienced an antidepressant effect of SD in the past. At each rTMS session 1000 stimuli were applied over the left dorsolateral prefrontal cortex at 10 Hz with an intensity of 110% resting motor threshold. For sham stimulation, a sham-coil system was used. Treatment effects were assessed with a modified version of the Hamilton Depression Rating Scale and a self-report well-being scale (BfS) before SD, after SD, during rTMS and 3 days after rTMS.

SD led to a highly significant reduction of depressive symptoms in the whole group as reflected by a mean Hamilton Depression Rating Scales score reduction of 56% (with omission of sleep items). In both the active and the sham-stimulated group, the symptom reduction remained stable for the whole observation period. No difference between active and sham rTMS was observed.

SD is capable of inducing pronounced antidepressant effects. In contrast to a previous study, active rTMS was not superior to sham rTMS in stabilizing the antidepressant effects of SD, which was mainly due to a pronounced effect in the sham group in this study population.