Objectives: Repetitive transcranial stimulation (rTMS) affects dopaminergic secretion in the prefrontal cortex. Attention deficit hyperactivity disorder (ADHD) had been suggested to involve dopaminergic prefrontal abnormalities.
Methods: In this crossover double-blind randomized, sham-controlled pilot study, patients diagnosed as having adult ADHD received either a single session of high-frequency rTMS directed to the right prefrontal cortex (real rTMS) or a single session of sham rTMS.
Results: A total of 13 patients (seven males, six females) who fulfilled the criteria for adult ADHD, according to DSM-IV criteria gave informed consent and were enrolled. There was a specific beneficial effect on attention 10 minutes after a real rTMS course. The post-real rTMS attention score improved significantly (M=3.56, SD=0.39) compared to the pre-real rTMS attention score (M=3.31, SD=0.5) [t(12)=2.235, P < 0.05]. TMS had no effect on measures of mood and anxiety. The sham rTMS had no effect whatsoever.
Conclusions: Our findings should encourage future research on the possibility of amelioration of attention difficulties in patients suffering from ADHD by using high frequency rTMS directed to the right dorsolateral prefrontal cortex. (NIH registry NCT00825708).