Acute effects of repetitive transcranial magnetic stimulation on attentional control are related to antidepressant outcomes.
BACKGROUND
Repetitive transcranial magnetic stimulation (rTMS) applied over the dorsolateral prefrontal cortex (DLPFC) is a new treatment procedure that holds promise of more insight into the pathophysiology of depression because the DLPFC may play an important role in the interplay between emotional and attentional information processing. We sought to investigate whether acute neurocognitive effects of rTMS are related to antidepressant outcomes.


METHODS
Between January 2005 and May 2007, we examined the effects of a single session compared with 2 weeks of rTMS over the left DLPFC on cognition and mood in therapy-resistant patients with depression. We used a crossover placebo-controlled double-blind design and differentiated rTMS treatment responders and nonresponders. We used a task-switching paradigm to measure cognitive function.


RESULTS
After 2 weeks of high-frequency rTMS over the left DLPFC, depressive symptoms improved in more than half (53%) of our therapy-resistant population. After a single session, mood did not improve but attentional control was increased solely within our group of treatment responders.


CONCLUSIONS
Our results should be interpreted as preliminary because our sample was small and because the cognitive task we used has not been tested for validity and reliability. In addition, despite minimal stimulation of the DLPFC during sham stimulation, it is possible that the stimulation was partially active. Finally, benzodiazepines may have had impairing effects on the attentional task.


CONCLUSIONS
Cognitive reactivity after a single session of rTMS may hold promise as a predictor of beneficial treatment outcomes. Moreover, within the group of responders, attentional control appears to play an important role in the progress of mood disorders.
Vanderhasselt
Marie-Anne
MA
Department of Psychology, Ghent University, Ghent, Belgium. MarieAnne.Vanderhasselt@UGent.be
De Raedt
Rudi
R
Leyman
Lemke
L
Baeken
Chris
C
D000328:Adult; D000339:Affect; D000928:Antidepressive Agents / Q000627:therapeutic use*; D001288:Attention / Q000187:drug effects* / Q000502:physiology*; D003866:Depressive Disorder / Q000188:drug therapy* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000502:physiology; D050781:Transcranial Magnetic Stimulation; D016896:Treatment Outcome; D055815:Young Adult
D000928:Antidepressive Agents