Can a behavioral intervention enhance the effect of repetitive transcranial magnetic stimulation on mood?

Background

One of the few novel treatments developed for major depression in recent years has been repetitive transcranial magnetic stimulation (rTMS). Despite mostly promising results, 50-60% of patients do not respond to rTMS. Therefore, it is important to investigate ways of enhancing the effectiveness of this treatment. To date, attempting to enhance the mood effects of rTMS via behavioral means has not been investigated. One such intervention involves concurrent exposure to affective stimuli that have been shown to result in activation of brain regions associated with emotion. This pilot study of ten participants investigates such an intervention.

Objectives

The aim of this pilot study was to investigate whether exposing participants to affective stimuli while they were receiving 5 Hz rTMS resulted in greater mood change compared with rTMS or affective stimuli alone.

Methods

Ten healthy male and female participants were exposed to affective stimuli while receiving rTMS. All participants took part in three counterbalanced conditions conducted a week apart in which they received rTMS (active or sham) delivered to the left dorsolateral prefrontal cortex (DLPFC) combined with affective stimuli (positive or neutral). To measure the impact of the dual intervention visual analogue mood scales and an affective go no go task were conducted pre- and post intervention for each session.

Results

There was no effect of any rTMS condition on performances on the affective go no go task, or on any of the visual analogue scales.

Conclusions

The current data do not provide support for the use of affective stimuli during rTMS. Methodological limitations that may have contributed to the lack of significant findings are discussed.

Keywords: transcranial magnetic stimulation, affective stimuli, mood